Bantin's Blog - Using Your BC.

Be warned, this is a particular hobby-horse of mine.

Dame schools were an early form of a private elementary school in English-speaking countries in Victorian times and they were later considered inadequate because they often relied on the older children teaching the younger ones what they had previously learned. In this way misinformation was often compounded and no new ways of teaching could evolve using this method.
Because diving is taught in the same way as those Dame Schools, a lot of technique gets passed down from generation to generation and in that way it does not evolve. A classic example is that of the way we release air from our BCs during and ascent. You've probably noticed that your BC comes with a selection of dump valves but only one inflation valve and conventionally this is positioned at the end of a long corrugated hose.
This was because when BCs were first invented they had no direct-feed of gas from the diver's tank. They had to be fed orally, the diver taking out his regulator and blowing some air into the oral inflation valve when required. Similarly, during an ascent, excess was released through the same valve, holding it high above the rest of the BC. To enable both of these manoeuvres, the oral inflation valve was positioned at the end of a flexible corrugated hose. Most BCs available today still feature this hose although they don't actually need to. After all, a drysuit is used in the same way, adding air during a descent and releasing it on the way back up, but without the need for any corrugated hose attached to the suit. A hose-fed inflation valve and a dump valve are all that's required. If the corrugated hose were essential, all drysuits would have them.
Indeed, there are some BCs available today that are equipped just like a drysuit with only an inflation valve and dump valves and no corrugated hose yet they have not proved popular in the marketplace. Why not?
Diving instructors were not born underwater. They all had to learn to dive in exactly the same way you did. The first ones to learn with a BC were taught to blow air in via the oral inflation valve and release it in the same way. At that time it was the only option. Once they became instructors they taught their trainees in the same way.
Once direct feeds were available, they were eventually adopted but old school instructors did not want to forego the original method of use complete with the corrugated hose. Those they taught, who went on to become instructors themselves, compounded this phenomenon.
Fast forward forty years and instructors are still teaching trainees to dump air using the oral inflation valve, raising the corrugated hose to do so. Why? Because that is how they were taught themselves.
So what about those dump valves that most BCs also come with? As usual, there will always be some misinformation offered to make the excuse for not using them. Some say that if you pull the cord on a shoulder-mounted dump valve it releases all the air from the BC in one quick whoosh. That isn't true. Try it. They are as progressive in their action as the older method.
In fact, many of these valves are so designed that they release the air without letting much water back in the other way. That's not what you can say about using the oral inflation valve.
Some divers end up with their BC full of water. Even if you do, by fully inflating the BC while floating at the surface and pulling the lower dump valve, the one located near your kidneys, you can squeeze most of this water out before you need to climb a boat ladder. Remember, a litre of water weighs a kilogram once you are airside and that's more weight to carry and climb the ladder with.
Don't be afraid to use the dump valves of your BC. They are positioned in the right place (the lower one is useful when making a quick head-down descent from the surface and you need to lose surface buoyancy) and are designed for the job. As I said earlier, there are some BCs available that eschew the corrugated hose altogether, treating it as something of an anachronism.
So what is the oral inflation valve actually intended for? If you are floating at the surface and need to top-up the air in your BC, you can do this by mouth just as you might top-up the life jacket that is stowed under your seat in the aircraft you went on holiday in. Of course, there are some kit manufacturers who pander to the resistance of some divers to take on board modern developments in kit and these provide BCs with only a corrugated hose and no dump valves. They still work just as you could even use an inverted plastic carrier bag for buoyancy control. It's just not as convenient!

Happy diving - John Bantin

Bantin's Blog - Choosing a BC

CHOOSING A BC

You may have read my blog explaining buoyancy control and why you need a BC. Actually, you need a BC for three distinct purposes. The first is to enable you to wear your tank on your back, or even side-slung as is a modern fashion with a few divers who want to emulate intrepid cave divers.

The second is to give you support or flotation at the surface. When inflated, you need it to float you comfortably in a vertical position. In fact, the earliest BCs were called Adjustable Buoyancy Life Jackets although with no permanent flotation this was something of a misnomer. The third reason is to allow you to use it for buoyancy control.

Ask on a diving forum what sort of BC you should buy and the inevitable answer will be "a wing-style BC with a stainless-steel backplate, because you're going to need it one day." They assume you are going to eventually become a technical diver.

It's true to say the majority of dives done world-wide are with single tanks so telling you to get something suitable for use with multiple tanks can be very misleading. People who get into multiple tank technical diving are very much in a minority and even they will be using inappropriate equipment if they use such a BC for an ordinary leisure dive while away on holiday.

A conventional jacket-style BC is far more appropriate for this. Why? Because such an item usually comes with one or more pockets for carrying ancillary kit such as a surface marker buoy or safety sausage and other items such as a reef hook or a small underwater lamp.

A lot of nonsense is often talked about attitude in the water, citing the idea that a wing-style BC will let you swim in a better horizontal position. The truth is that the air in either style of BC will always migrate to the highest place under water, which is directly behind you shoulders in both cases. The difference comes when you fully inflate the jacket-style BC because once the top of the buoyancy cell is inflated, the lower part that is positioned towards the front underwater also inflates and that should sit you upright in armchair comfort while you wait to be picked up by your dive boat.

So what's the point of a wing?  A wing-style BC can have an enormous buoyancy cell that will be adequate to float you and several heavy steel tanks. At the same time it offers an uncluttered chest area so that a diver can hang all the regulators that go with those tanks, while the metal backplate offers more locations to stow kit.

Loads of potential lift must be a good thing, mustn't it? As a rule-of-thumb, you don't need more lift than you have weight on your belt. That is especially true when using aluminium tanks popular at leisure diving centres abroad. A big wing, fully inflated, with tend to thrust you face down at the surface if used with a single tank. It's not the right tool for the job. A BC with, say, only 10kg of maximum lift can be quite adequate for this purpose.

If you like the idea of the uncluttered chest area, you can get a leisure diving wing-style BC with a more appropriate size buoyancy cell. It's a question of personal choice.

When you come to pack your bag to travel, it will be apparent that the BC might be the heaviest item of diving equipment you have. A good solidly built BC might be very hard wearing and great for diving locally but at this time you'll wish you had a more lightweight one. The cost of an extra BC for foreign holiday use can soon be recovered in the savings on excess-baggage charges. Whether conventional in layout or a wing, there are now many lighter weight BCs available and some can even be rolled up to form a compact shape in your bag.

Get the right tool for the job. Don't be bullied into getting the wrong BC just because a disinterested party on the Internet has given you a bad steer. When you visit Mike's Dive Store, explain exactly what sort of diving you need it for and the staff there will help you to choose what's appropriate for your needs. It's in their interest to make sure you are happy because happy customers are regular customers. There's a large range of different solutions to the BC choosing problem and it's important that you end up buying the right one - and if you do take up cave diving or feel you want to side-mount your tank/s, they'll be ready with the right solution for that too!

My next blog will be about actually using your BC under water. It includes a particular hobby-horse of mine.

Happy diving - John Bantin

Bantin's Blog - Buoyancy Control

Buoyancy Control

It amazes me that I still see divers who do not seem to have managed to master good buoyancy control.

Ships float because they displace a greater weight of water than they weigh themselves. That's because, although they are made of steel, they have a great amount of airspace within them. A man in a lifejacket floats for very much the same reason. Although, by and large, the human body is neutrally buoyant the additional flotation of the lifejacket tips the balance in favour of floating. Alas, our heads tend to be heavier than the water they displace, which means recently drowned people are usually found floating head-down so it's important to wear the lifejacket in such as way as to support the head.

As divers we contrive to be neutrally buoyant. That is to say we neither float up nor sink. We simply want to be able to go effortlessly in the direction we choose. Of course, some of our equipment is heavy whereas other parts would float it left on their own. The wetsuit, made of neoprene, if full of tiny bubbles of material that contain gas. Together, the aggregated effect of these floating and sinking parts usually results in a diver needing to add some ballast in the form of lead weights.

The biggest influence on our buoyancy is our own lung volume. It can vary as much as six-litres by simply inhaling or exhaling. By controlling how much you breathe in or exhale you can make adjustments to your buoyancy far quicker than fiddling with some external device. If you find yourself starting to float up, exhale before adjusting your BC. Similarly, if you find you are descending more than you like, initially inhale a larger lung volume.

When you learn to dive the instructor usually loads you up with more lead than you would otherwise need. This is because he needs you to kneel comfortably on the bottom while you learn new diving skills. New divers also tend to be a little anxious and that entails them breathing more heavily than they would do otherwise and big lung-volumes add buoyancy.

Good instructors teach buoyancy control. It's quite difficult to master this in the shallow water of a pool because the dramatic depth changes in the shallows has such a quick effect on the buoyancy of your suit and the expansion or compression of the gas in those tiny bubbles of neoprene. The same goes for any air in your BC. The net result is that few new divers master buoyancy control until they are diving in deeper water.

Too often new divers wear too much additional lead because that is how they originally learned. Dive guides the world-over spend their time convincing these over-weighted divers to shed some of this additional weight.

A BC or BCD (buoyancy control device) is used to maintain neutral buoyancy at any depth. Do you know why it's beneficial to use one? Would it surprise you to know that pioneers of diving such as those divers on Cousteau's team didn't bother? Well, they didn't need to because they eschewed wetsuits. It's the wetsuit that makes a BC necessary. With the thin wetsuits they used when they did use such things, these pioneer divers did all their buoyancy control by varying their lung volumes.

As you go deeper, the integral bubbles in the neoprene of the wetsuit get compressed and your suit loses volume (along with insulation properties). This means you displace less water and appear to get heavier. You add air to a BC to compensate for this. As you ascend, you must release this air gradually in the same way.

This brings us to drysuits. A drysuit has the ability to be fed with air just like a BC. You do this to keep its overall volume constant. If you contrive your weights so that you are neutrally buoyant in a drysuit just under the surface, you should be able to maintain that neutral buoyancy by keeping the suit at the same volume by adding small amounts of air as you go deeper and at any safe leisure diving depth.

You don't inflate the suit despite the valve being called the inflation valve. The air in the suit remains at the same volume but it gets denser as you go deeper, it gets compressed and you add more. Some say that air 'sloshes around'. That only happens if you started with too much air in the suit when adjusting your weights for neutral buoyancy just under the surface. The term 'inflation valve' is misleading. You should not inflate the suit while under water. You should only maintain it at constant volume.

Of course, the one variable in all this is the amount of gas you are going to use during the dive. Gas has a mass and a full tank can be around 2.5kg heavier than an empty one. So if you are doing a buoyancy check with a full tank don't forget to allow for this.

Get your buoyancy right just under the surface so that you neither float nor sink whilst horizontal, with normal relaxed breathing and the minimum amount of lead, so that enjoy neutral buoyancy throughout the dive. By the way, the only real reason you need a BC with a drysuit, apart from the additional safety offered by its obvious redundancy, is to give you surface support in the right part of your body rather as with a lifejacket.

Happy diving - John Bantin

Bantin's Blog

Photographing Seahorses

There's been a bit of fuss recently in the diving press both here and abroad about photographing seahorses. The self-proclaimed leader of the British Seahorse Trust insists the light from underwater photographers flashguns kills the animals whereas the only proper research done into the subject by David Harasti in Australia proves otherwise. You can see the full document here: Journal of Fish Biology (2013) doi:10.1111/jfb.12237, available online at wileyonlinelibrary.com.

It turns out that it is not the light effect but the inappropriate handling of the seahorses that does the damage. That said, it seems it is now illegal to photograph seahorses in Britain using any form of artificial light. Of course, seahorses are found all over the world and millions are taken every year to satisfy the demands of traditional Chinese medicine.

During my career I photographed animals as disparate as dogs, cats, chameleons, chickens, chicks, ducks, horses and toucans for use in various big advertising campaigns with equal success. This was despite the fact that the amount of energy discharged for each picture was in the order of five hundred times more than from the most powerful underwater photographic strobe unit and made a 'pop' that certainly would make an unsuspecting human bystander jump. That was because in those days we were shooting on big sheet-film cameras that needed a huge amount of light. The fact of the matter is that the reaction times of animals are so much faster than that of man that they are not startled.

When a larger marine animal like a turtle or a shark is embarked on feeding, no photographer is likely to put it off its stride. With smaller animals, it is merely the sheer bulk of the photographer that causes alarm since in the marine world it's normally the small that get preyed on by the larger predator.

That said, the sight of a huge group of underwater photographers surrounding a little hairy frogfish at Lembeh Strait or somewhere equally popular with macro photographers must cause the casual viewer to wonder if, with all the photographers' strobes popping off at frequent intervals, the little animal is not being harmed in some way. It must be so much worse for tiny pygmy seahorses.

Studland Bay in Dorset is a popular destination during the summer months for pleasure craft mainly coming from nearby Poole Harbour. They each drop an anchor, many leak diesel or other hydrocarbons, and often sewage is pumped from their heads. Add to that the run-off of chemical fertilizers (phosphates and potash) from Dorset County's heavily farmed land and we can agree that none of it is very good for the marine life. It's no surprise to hear that the seahorse population in Studland Bay is declining. 

The Seahorse Trust lays the blame squarely at the feet of underwater photographers. However, its annual report and recommendations is based on observations and anecdotal evidence. Has the British Seahorse Trust got it wrong regarding the flashes of light from underwater photographers' equipment? It's an emotive subject and the debate continues. What do you think? In the meantime, when it comes to marine life and diving, look but don't touch!

Happy Diving - John Bantin

Suunto D4i Novo Has Arrived!

ADD A BIT OF COLOUR TO YOUR DIVE LIFE IN 2014 WITH THE NEW SUUNTO D4I NOVO!

The great all-rounder now comes with vibrant color options and a new strap

Suunto has launched new color versions of the popular dive computer Suunto D4i, which is now in stock and ready to ship for next day delivery! The product features stay the same, but they now come in fresh new colors and design.

The new-look Suunto D4i Novo is available in black, white, blue and lime. As well as the renewed design, the Suunto D4i Novo also features an all new, soft silicone strap, ensuring maximum comfort as well as a superb fit. The case and strap are color-matched for a consistent look, bezel and mask prints are new and the buttons are made of metal.

Sleek and lightweight, the SuuntoD4i Novo also offers versatile functionality. With four dive modes — including freediving — Suunto RGBM algorithm, and the option of wireless integration, it's the dive computer of choice for all divers looking for a colorful and lightweight dive computer.

To make it even easier to sync and share extraordinary diving adventures, Suunto also offers the updated DM4 software, and easy synching with Movescount.com sports community and logbook.

About Suunto

Suunto was founded in 1936 by Tuomas Vohlonen, a Finnish orienteer and inventor of the liquid-filled field compass. Since then Suunto has been at the forefront of design and innovation for dive computers, instruments and sports watches used by adventure seekers all over the globe. From the highest mountains to the deepest oceans, Suunto physically and mentally equips outdoor adventurers to conquer new territory.

Suunto's headquarters and manufacturing plant is in Vantaa, Finland. Employing more than 400 people worldwide, Suunto products are sold in over 100 countries. The company is a subsidiary of Amer Sports Corporation along with its sister brands Salomon, Arc'teryx, Atomic, Wilson, Precor, and Mavic.

Prescription Dive and Snorkel Masks - John Bantin

Prescription Diving and Snorkelling Masks

It's always nice to get something new. My favourite old dive mask had seen better days. Its silicone skirt had yellowed and stiffened with time and probably too much exposure to tropical sunlight so I got hold of a new one. 

I'm very lucky in that I seem to have a face that gets along with almost any mask despite my ill-groomed facial hair and the latest TUSA Freedom Ceos dive mask was said to have a super-flexible silicone skirt so fit was never a worry.

They say that there are two types of people past middle-aged. Those who wear glasses and those who never read books. What was a worry was the fact that in common with many people over the age of forty-five (and I'm well over that) my eyesight is no longer as good as it was. Similarly, many people suffer short-sightedness from birth and wearing a mask in conjunction with contact lenses can inhibit the freedom to take it off underwater. I still remember the time it took me to feel carefully along the bottom of a swimming pool in a desperate search after one of my trainees lost a contact lens during a mask removal exercise. Naturally, I found it. A good instructor as ever, I wasn't ever going to let anything spoil my trainee's day.

When it comes to choosing a mask, if you are so afflicted by imperfect vision, you'll want a dive or snorkel mask that will take prescription lenses. It's a much better option than battling with contact lenses underwater. Now, I might add that you may not need lenses that completely match your prescription since even the clearest seawater is quite poor optically but an approximation with do and go a long way to getting you the maximum enjoyment from getting your head underwater.

If you want to be good at something, you've got to practice. I took home my shiny new mask and a set of lenses with the intention of installing them in the mask. I've worked in the diving industry for a generation and yet I baulked at taking the mask apart. Even a phone call to the distributor (who sent me a special tool for the job) left me pondering how to get the old glasses safely out. It's simply that every mask seems to be different and I'd only done this about once every five years. If I had been more clever, I should have let Steve at Mike's Dive Store do it for me. He does it virtually every day.

Well, I managed to successfully install the new lenses at the end. I then merely had to get rid of the inevitable and invisible silicone deposit that gets on to the inner side of the mask glass during manufacture and causes that annoyed fogging problem. The safest way too do that it to rub a bead of old-fashioned white toothpaste around the surface to gently abrade the silicone deposit off. Otherwise, it gives an edge for tiny droplets of moisture to cling to, precipitated out of the damp air inside the mask while you are using it.

After that, each time before you go under water, simply spit on the inner side of the mask glass and rub the saliva around before giving it a rinse in seawater. Don't bother with packaged products that promise to do this job. Spit is free and you've got plenty of it and I'd hate to think where the proprietary product is sourced. 

When it comes to choosing a skirt, the choice is usually between clear silicone or opaque silicone. Some divers swear that a mask with a black skirt gives them better vision. I suggest that a transparent skirt gives you a better feeling for what's around you. Just like driving a car and looking through the windshield, the side windows of the car don't destroy your forward vision but certainly make the car less claustrophobic. That said, some like to look like Zorro or Batman with a black-skirted mask and who am I to argue with that? My best advice is to get one that fits you well with lenses that suit your eyesight. Enjoy your diving or snorkelling.

John Bantin

Inon Underwater Photography Day at Mike's Dive Store London! Saturday the 7th of December

Come and Learn About Underwater Camera Equipment And Winning Underwater Photography Techniques

Mike’s Dive Store is the only official INON UK Underwater Photography Academy and INON UK underwater camera retailer in London.  Mike’s Dive Store already has two experienced underwater photographers on the staff.  Christian Deakin is an INON UK Level One underwater photography instructor and Joe T Bourne is also an accomplished underwater image-maker.   Mike’s has long specialised in underwater camera equipment. In the run up to Christmas Mike’s Dive Store will have a special open day where you can learn from INON UK experts about choosing and using underwater cameras and accessories to help you get batter pictures you can be proud of.

On Saturday December 7th Mike’s will have in - store presentations from INON UK’s founders Lisa Collins and Steve Warren. There will also be lots of INON underwater camera equipment to look at from strobes to video lights to lenses and stacks of accessories. Along with specialist one to one advice across the counters from Lisa and Steve and some very special promotional deals, there are also talks to help explain the ins and outs of choosing underwater camera equipment that will be especially helpful if you are new to underwater photography.

The three talks are about selecting underwater strobes and video lights, choosing lenses and winning composition skills.

Selecting Underwater Strobes and Video Lights

For many types of underwater photography using additional lighting is a must. It’s used to light up subjects at night, in caverns and wrecks or under overhangs. It is used creatively to emphasise textures or add points of interest. And, most of all, it is used to put vibrant colours back into your underwater pictures. But there are so many underwater strobes to choose from with lots of often confusing features, making a choice can seem very complicated. Which features and benefits are going to be important to you? Would you be better off with a video light instead? How do you even aim it properly to prevent backscatter? Do you actually need two lights?

Steve Warren is both a stills photographer and sometime professional cameraman. Just back from lighting a complicated night sequence for TV, he can explain the desirable features to look for in strobes and video lights and give you the knowledge to make informed choices about which lighting is best for you.

Choosing Lenses

The wealth of subjects we see underwater range from the largest whales to the tiniest crustaceans. Visibility may stretch to over 60m, but can be barely centimetres.  It is asking a lot – too much in fact – for any camera to capture all that we experience on our dives and would wish to share with others. The solution is to choose accessory lenses that best match our subjects and likely visibility. Compact camera users and some mirrorless camera owners enjoy the huge benefits of being able to use wet lenses – like INON’s range – which can be changed underwater. This lets you react to whatever you see and be opportunistic and provides the flexibility to photograph a wreck vista one moment and a frame filling photograph of a tiny nudibranch on its deck seconds later.

In this talk, Steve will explain the roles different lenses play for different types of subjects. He’ll also cut through some of the jargon and misinformation that surrounds this subject and leads people to make expensive buying mistakes, which lead to disappointing images.

Winning Compositions

Owning the best equipment and diving the best photo destinations won’t help you make great pictures if you don’t follow a few simple rules of composition. Learning to see a picture is a skill anyone can acquire. But, for underwater photographers, this is the subject many underwater photography instructors avoid! So it is hard to learn this essential skills set from others. For Lisa Collins, shooting winning compositions is all part of her job. As a photo – journalist shooting  main features for Diver Magazine she has to be able to arrive at a destination she’s never been to before and shoot images that not only reveal the signature species and locations of that location, but look great to.

In this presentation Lisa will share with you the rules that will help you make great photographs on your next dive trip. She’ll discuss what makes a good subject, how to frame it for best effect, the importance of using complimentary colours and the creative thinking that goes into making each photograph in her magazine submissions.

Come along on Sat the 7th of Dec to answer all those questions you have been accumulating over the years! And maybe even to buy something either for your buddy or perhaps an early Christmas present for yourself!!

Dive Computers with Air Transmitters

Gas-Integrated Dive Computer Transmitters

Let’s admit it. We divers are a funny lot. Although we are often seen by others as being very adventurous in what we do, we are usually very unadventurous in the way we do it and that is especially true when it comes to equipment innovation.

Back in the early ’70s, divers used tanks with J-valves. When the air in the tank was depleted, the regulator became harder to breathe from. The diver then pulled the J-valve release, which allowed access to the last quarter of the tank’s supply, the regulator freed up and it was time to ascend. It sounds a bit primitive doesn’t it? Can you believe that when submersible pressure gauges (SPGs) were first introduced they were met with some resistance?

Some divers saw them as an additional hazard, an additional failure point. They thought they could easily explode with so much pressure inside them and a legacy of that is seen today when trainee divers are still taught to hold the gauge away when they first turn a tank on. I haven’t ever heard of a pressure gauge so exploding but I’m sure it must have happened – once!

Air-integrated computers have been with us for some time. They were resisted as well at first. Myths and misinformation grew up surrounding them. Because they made a prognosis of remaining air-time based on a previous breathing rate and the actual depth the diver is at, many who should have known better declared that they preferred to know the remaining pressure in their tank, as if that information was not available as well.

I would say that we all understand the concept of remaining air-time in minutes balanced against the total ascent time required (hopefully the former is always greater than the latter) rather than some pressure reading but it took time for this advance to become accepted. It was caused by a general distrust in technology. That’s ironic when we trust technology so much in so many other different ways – as aeroplane passengers, for example.

Of course there were some defects in gas-integrating transmitters when they were initially invented, notably an occasional loss of pairing between transmitter and wrist unit. Today’s computers pair permanently with their wrist units so the case of failing to get a tank reading under water with one that needed to be paired immediately before diving has faded into the past. There was also talk of photographer’s underwater strobe units interfering with the signal. I’ve never encountered that and I’ve used a lot of different strobe units as well as a lot of different computers.

Redundancy

Bantin's Blog - Redundancy

My daughter-in-law used a courtesy car from her garage while hers was being worked on. It was a new Merceded C180, a very nice car. That is until she drove over a bottle and wrecked a tyre. Luckily, although she was 70 miles from home, she was only 70 metres from my house, so I took care of things while she went on to her job at the nearby film studios.

All I had to do was to remove the wheel and take it to a tyre dealer for a replacement. It was at this point I discovered that the car had neither a spare wheel nor a jack. So much for advances in modern technology. I had to wait all day for a rescue service to take the car to a garage. Luckily this all didn't happen somewhere remote.

This happily brings us to the subject of redundancy. When you are only 20 metres under water, you are a long way from 'home'. It's not a place to find that you need a 'spare' that you don't have and unless your buddy is actually holding your hand, the spare carried there might be well beyond reach.

So what are the spares you should carry? 

Firstly, let's think about spares that could save a dive before you even get in the water. A spare mask strap and a spare fin strap in your bag could save the frustration of finding the first one break just as you put your mask or fins on. A spare regulator in your bag can save the day if you're diving far from home. These things never fail when they are sitting in a cupboard. It's worth carrying a spare dive mask too, if you're travelling and deep divers take a spare mask with them to avoid disaster under water. Every diver should be competent enough to handle a broken strap while diving and you'll soon discover a mask will work without one if you need to.

A couple of spare tank O-rings (DIN or A-clamp) are always worth having too.

So what are the spares you should carry under water?

If you were working professionally as a diving instructor might, the HSE demands that you carry an independent air supply. That makes sense. If you are diving in the poorer visibility we encounter in home waters, it make sense for every diver to carry spare gas so why not invest in a pony cylinder (a smaller cylinder that you wear alongside the main) complete with its own regulator, or even simply twin two standard cylinders? Just be sure they are not too heavy together for you to handle.

BCs are very low-tech affairs but if you are wearing a drysuit and not over-weighted, that will give you the redundancy you need for cold water diving. If you are warm water diving and not over-weighted, you should always be able to swim up easily, even if your BC were to suffer a rare failure.

I've already mentioned in a previous blog about having two dive computers on dives. If one should fail (and everything fails at some time or other) you will need to wait 24 hours before continuing to dive and if you're away on an expensive diving trip, you won't be happy doing that. 

Dive Torches are much more reliable than they used to be but people are just as bad as ever so there's always the chance that you forgot to fully charge yours or even didn't reassemble it faultlessly afterwards. It's not very nice to be left in the dark. The simple solution is to carry a back up in the pocket of your BC and small inexpensive dive torches can have big performances nowadays.

Happy diving. - John Bantin

Electronics and Dive Computers - John Bantin

Electronics

The big expensive outboard motor of my boat was very sophisticated but for some unknown reason one day it simply stopped working. Three different mechanics came to look at it consecutively, one Spanish, one German and one British. In consequence I learned the term 'black box' in three different languages. The electronics were replaced and everything was fine. Many of us have experienced similar failures of electronics in our cars. 

PCBs are mainly now sourced in the Far East. They are remarkably cheap. 

It's almost impossible to buy electronic goods these days without a PCB in it. Even modern toasters have them. What electronics do we use in diving? Our diving computers.

When these were first introduced in the early 1980s, they were made in Switzerland and would have cost around £3000 each at today's prices. They were certainly a luxury item. Today we can buy a diving computer for a few hundred pounds.

They are incredibly useful items and can be credited for the millions of man-dives made without any accident due to decompression illness. Of course, no manufacturer can guarantee that you personally will be always safe even if you manage your dive perfectly the way the computer demands but that's because the dive computer was not made for you exclusively. Everyone is physiologically different so the manufacturers try to build in an element of safety to their mathematical calculations to account for that - but you might be one of the very few outside those parameters. Nobody knows.

That said, diving computers are fantastic tools for leisure divers and I thoroughly recommend that every diver have one - or at least one. The problem arises when the black box strapped on your arm ceases to work. It could be battery failure or it could be worse.

You don't expect your toaster to last forever so why would you computer? You may say that your computer gets less use but remember that for every dive you do it continues to recalculate during your surface interval so that if you did 100 dives in a year it would almost be the equivalent of your computer working for 100 days.

PCBs are cheap. The major cost of a diving computer is in the research and development. Manufacturers want you to be a happy customer. They back up their warranties by simply replacing the unit from stock although some say they will try to repair if they can. It all depends on the resources of the company in the country you are in. In Britain, there are few actual manufacturers although one importer is the wholly owned subsidiary of its principal and has the resources to match.

So what am I saying? Buy a dive computer, understand what it does and use it for your dives. Appreciate the good value it represents and be happy to get some good years out of it. Be also aware that computer technology moves on apace. For example, computers that were oil-filled to keep them watertight cost a fortune to make and the same thing applied when it comes to changing the battery. They are no longer made. 

Your dive computer could be considered in the same way as that single electronic component in your car. If it stops working, you replace it. This blog was inspired by a letter I read from someone in America who complained that the very inexpensive computer watch he bought seven years ago had ceased to work and was no longer repairable under warranty. That's the way of the world.

By the way, reading the instruction book while decompressing is not a good way to use your dive computer. Safe diving - John Bantin

Dive Computer Algorithms

Dive Computer Safety

Any of the diving computer's that you can buy today at Mike's Dive Store will do their equal best to stop you getting damaged by decompression illness, provided you understand and follow the guidance they give. However, years ago it wasn't necessarily so. Some of them used philosophies that varied widely from the mainstream. I use the term 'philosophy' because it's all based on theory and every person is different so no diving computer manufacturer can guarantee that you won't get a bend. That said, considering the numbers of dives safely done world-wide each year, you've got to be very unlucky indeed.

Most diving computers allow you to add degrees of caution. You may be over-weight or over-age. You may have some health issues. None of these necessarily stop you diving but you should take them into consideration when setting up your computer before diving.

There used to be an Italian brand of computer that advertised the fact that it gave you more bottom time than others. This equated to less safety. Is that what you really want? Thankfully it soon disappeared from the market place.

More insidiously, a very popular brand of computer used to use an algorithm or mathematical model that was intended for no-deco-stop diving to depths less than 30m. That was fine as long as the user was aware of that but of course, often they were not. It gave lots of no-stop time up until the moment that the remaining no-stop time ran out, when it switched to a different table that often then required extensive time at shallow depths before the user could be assured that it was safe to surface. Of course, this usually happened towards the end of a dive at a time when the diver was getting low on air. We saw lots of these computers tied off and dangling beneath boats at around 6m deep while the owner climbed out and went for lunch - albeit feeling a little insecure.

You can still buy computers with this algorithm and provided you intend to use it to manage no-stop times and never go beyond that, they'll probably be fine. However, these same computers now have dual algorithms installed and you can opt for the one that ties in with other mainstream computers. 

The fly in the ointment is that few of us bother to read the complex instruction manuals that usually come with computers so I've often witnessed divers doing complex leisure dives unknowingly with an inappropriate algorithm.

I was in Truk Lagoon when my buddy, so equipped found he had 25 minutes more no-stop time while I was decompressing on the trapeze hung under out boat. He continued to dive at around 20m deep and didn't get bent but we have no way of knowing how close to the edge he came.

A lady diving alongside me queried the fact that her two computers of different makes gave widely varying information. I simply later set the offending one to the algorithm that matched the other and she spent the rest of the week much happier.

If you buy a computer fitted with such a dual algorithm, be sure ask the person that sells it to you to set it to the algorithm appropriate to the type of diving you'll be doing; shallow no-stop dives or dives where you go a bit deeper. It might be agued that the second type errs on the side of caution. I'd say it does no harm to hang around at 6m or less as might be mandated, provided you've got sufficient gas in your tank. Stay away from the edge!

Happy diving. - John Bantin

Diving Certification

We've all been wowed recently by the YouTube footage from those crazy guys who jump out of helicopters or off the tops of high mountains wearing nothing more than a wing-suit to aid their safe landing. They know the risks they take.

It's the same with lots of action sports. You can kayak over a waterfall or ride your mountain bike down an incredibly steep hill. You can even buy fishing gear and a lot of beer and go and sit at the edge of some deep water without anyone questioning whether you can swim. It's probably only the high financial outlay and the risk to the animal that people take horse-riding lessons. If it goes wrong you have no one to blame but yourself. It's down to you.

We live in a free country and there's nothing to stop you from buying a bike and riding it where others might blanche at the prospect. Neither is there anything to stop you from buying a full set of scuba gear and popping off for a dive alone in the ocean. That's your choice.

However, we also live in an age where safety has become paramount if there's any possibility of someone else getting the blame. This is why you need certification to embark on scuba diving if anyone else is involved with you.

After diving for more than thirty years, I was sent incognito by a magazine to enjoy a PADI Open Water Diver course at a dive school in the sun abroad. The object of the exercise was to write a feature about it.

None of the other would-be divers knew me and I noticed a certain level of apprehension the first morning among my wide-eyed companions. I too was a little tense since the course was to be conducted in German, a language I didn't speak. I bluffed my way through and my years of underwater experience meant that I became a star pupil once I fathomed out what was wanted of me.

Over the period of four days, my previously nervous companions visibly grew in confidence as they discovered that scuba diving was not nearly as difficult as they might have imagined. At the end of the course they were all certified.

We then spent the next few days doing some easy shallow leisure dives during which time it struck me that these people who had enrolled in the classroom on that first morning knowing nothing about diving had, in the course of a few exercises and dives, become within that short time frame, experts in their own eyes.

Assuming I too was a newly qualified open-water diver, between dives I got lots of uninvited advice about my equipment choice and where I should go diving. For example, I was told that I had the 'wrong' regulator and that I didn't need a diving computer.

Scuba diving is almost unique among leisure activities in that you need to embark on a structured course and are eventually issued with a certificate that proves your proficiency. Of course the PADI OWD certification is only the start. You can go on to obtain far greater levels of certification for more advanced levels of proficiency and whatever level you achieve there will always be someone with a higher level than you.

Scuba diving is not normally a competitive sport. Those that compete at the extreme level usually have only one destination. There are bold divers and old divers but few old bold divers. However, our human condition lends itself naturally to compete. When you learn to dive, you'll take on board everything your own instructor tells you. Inevitably, he will have his own personal take on things despite adhering to the training standards of his particular agency. Later, you will find yourself in the company of other divers who maybe learned slightly differently or with alternative training agencies. They are not wrong, neither are you.

Be warned that you will meet people who try to enforce their own opinions and points-of-view about diving technique upon you. Some will be worth adopting while some will suffice to merely aggrandise the teller. (The Internet is awash with the opinions of such keyboard warriors.) Learn to pick up new ideas but reject those that are merely a different way to skin the same cat. Don't be demoralised. You've got a certificate too.

It's the certification phenomenon in scuba diving that lends itself to those that want to prove themselves instant experts. Nobody tells the wing-suited flier he's doing it wrong. He'll know that, if he is, the moment before he hits the unforgiving hard surface.

Safe diving - John Bantin

Bantin's Blog!

For more than 21 years, John Bantin wrote for Diver Magazine. His articles were about diving experiences at diving destinations, diving techniques, his famous equipment tests and reviews, and even simple opinion pieces. His vast library of underwater pictures served not only to illustrate his own work but that of many others. He never shied away from saying what he thought even if it might be controversial. He always believed in engaging the reader emotionally even if it meant making them angry. He certainly made food for thought. Now he's promised to write a regular weekly blog for Mike's Dive Store. It will always be informative, entertaining and often thought provoking. We might even, one day, persuade him to tell us the back-story on why he walked away from what was apparently the best diving job in the world.

Diving With Sharks - John Bantin

Sharks

One of the first things non-divers ask you when you first embark on a scuba-diving course, is if you aren't worried about sharks? Everyone remembers their first shark encounter under water. Mine was lying torpidly on the seabed, undoubtedly a shark but disappointingly inactive nevertheless. It was a nurse shark. Later, I came across a white-tip reef shark. I was able to record it on my underwater Handycam because I managed to corner it in a cave. It swam round furiously looking for a way out before it escaped in a rush right past my ear. I found my heart was beating fast but the shark had been rather smaller and rubbery than I anticipated.

Years later, I went to my first shark feed. There were about a dozen proper shark-like sharks circling round while an intrepid dive guide fed them with scraps of fish at the end of a spear. This was an adrenalin-busting experience and limited to film in my camera, after a few minutes I'd shot my 36-frame ration and had to head up back to the boat to reload.

The sharks were still there when I got back shortly after and I shot a second 36-frames worth before again retreating to the boat to reload. It was incredibly exciting. These Caribbean reef sharks were as big as me and were inclined to bump into me if I got in the way between them and the hand-out of snacks. I rushed to reload my camera the third time and, in the excitement, failed to close up its housing properly. My heart was racing as I swam down to join the ominous grey shapes circling below but it raced even faster as I swam back up in a vain attempt to save my flooded camera.

I've dived in close proximity to many different types of sharks since then and photographed them too. Everything from the mass brawl of hundreds of little white-tip reef sharks squabbling over some unfortunate prey at night to the majestic whaleshark that hoovers up small fishes and plankton have been the subject of my lens. I've won prizes for my close-up wide-angle pictures of Great hammerhead sharks. Recently, a huge tiger shark, much bigger than me, grabbed my tank and swam off with me. It was a thought-provoking thirty seconds before I was unceremoniously dropped.

If you want to hear more about diving with sharks, what a great buzz it can be and where you can do it, come to my illustrated talk at the London School of Diving and Mike's Dive Shop Open-Day on Saturday 12th October at 2.00pm, next to Mike's Dive Store - click here for full details....

John Bantin

Friday Specials Club!

To make way for the new Gopro 3 we are selling the Gopro 2 Outdoor set with Underwater Housing for an incredible £199 (RRP £259) Just call Bristol or Chiswick now to get in fast!

SUP - Stand Up Paddle Board Launch at Mike's Dive Store London!

London’s first stand up paddleboarding store opening in Chiswick

Paddleboarding or SUP has been growing in London for 2 years since Active360 started running trips, lessons, races, board hire, parties and events.  Now you can try and buy equipment in West London.

On 28^th February Active360 are opening a new SUP store in Mike’s Dive Store in London W4. The shop will stock some of the best boards, and paddles from top brands including Coreban, Qucickblade, Naish, Ainsworth, Liquid Shredder and SUP Love.      The store will also stock  wetsuits, paddling boots and thermal gear for winter paddling, drybags and many other things to make SUP fun and easy.

To kick things off we are inviting everyone to an opening party at the store in 113 Power Rd, W4 5PY. From 5.30 – until 9.30pm you can see our range of boards and paddles, including some never seen before in the UK.   You can also try paddling our SUP ergometer and compete for great prizes.  

Click here to find out more about our expedition to Arctic waters this summer  and our plans to run Greenland and Iceland SUP trips from 2014.  Also get updates on  Active360’s great range of courses, races, mass paddle events and trips and the new sUP Schools we are starting soon in Brighton and Mersea Island.

Free beers, wine, and snacks for early birds and a prize draw

Fridays Specials Club - Scubapro Spectra Mask and Snorkel Set

Buy a Scubapro Spectra 2 Dive Mask and get a Scubapro Spectra 2 Snorkel worth £25 for free! Yes Totally Free! Just call Bristol 0117 977 0562 or Chiswick 0208 994 6006 now!

WWW.MIKESDIVESTORE.COM

Friday Specials Club - Atomic Cobalt Dive Computer

Atomic Cobalt Dive Computer

We have one of these that has been used on one dive holiday 10 dives but is in immaculate shape - we have even replaced the front screen guard for the incredible price of £586 Usual RRP £889

The new Atomic Cobalt Diving Computer is the first of a new generation of computers that are easy to use, simple to use intuitive and easy to read with its brilliant OLED display. It is SIMPLY BRILLIANT!

The menu driven display is self-explanatory at every level and can be mastered in just a few minutes. This simplicity is in contrast to its powerful capabilities and the many advanced user functions available to those who wish to use them.

The full colour OLED display provides high contrast, sharpness and brightness that can be viewed at almost any angle.

Remember - you need to call one of the shops for the Friday Deal! Have a great weekend and hope you are diving somewhere or other!

Friday Specials Club - Hangair!

UK Hangair! RRP£49.95 Our Price £36

Hangair - yes it does exactly that - hang your suit up and it circulates air through it - amazing !
The UK HangAir® Suit Hanger feature a high power waterproof fan which pushed fresh, dry air into your suit.
Perfect for drying out wet suits, waterproof clothing or that slight leak at the end of the days diving.
A 5m long cable means you can plug it in in most places, while a wide design prevents damage to the garment.
As all drysuit divers will be aware, a damp drysuit is not the nicest smelling of items, but by drying it quickly, the HangAir® can eliminate the build up of any unpleasant odours as well  

 

Please remember that to buy any of our Friday Specials you need to call either Chiswick 0208994 6006 or Bristol 0117 9770562

Friday Specials Club! Oceanic Veo 3 Dive Computer!

This week in our Fridays Specials club we are offering the Oceanic Veo 3 Dive Computer at an unbeatable price of £175 the RRP is £285 saving you a massive £110! But rmember it is only for today and we only have two units available at this price! Either call Chiswick 0208 994 6006 or Bristol 0117 977 0562 now!