John Bantin has been a full-time professional diving writer and underwater photographer since 1990. He makes around 300 dives each year testing diving equipment.

WHEN I TRIED TO EXPLAIN to my Spanish friend that my German autobahn-gulper had an automatic gearbox, I was met with incredulity. Why would you want one if you knew how to drive a car? American friends would be just as incredulous at his response, for the opposite reason.
     Similarly, why would anyone who knew how to dive want an AquaPilot? Could it be that one day others will find it incredible that any diver ever managed without one?
     The AquaPilot GF is intended to take control of your buoyancy - automatically. It's the world's first air-integrated deco-computer, combined with an automatic buoyancy controller.
     The deco computer seems straightforward. It has a nice graphic of a tank which you can watch emptying, and I would put money on it using a Buhlmann ZH-L16 algorithm. The display has an annoying flicker, like a fluorescent light that's about to go out, but the main interest here is in the buoyancy control aspect.
     I was glad of the 10-hour flight to my diving destination. It gave me time to get to grips with the instruction manual, although for something meant to simplify buoyancy control, it gave me a headache. I didn't understand everything until I got the unit under water, and by that point I naturally didn't have the book.
     Before you dive, you program in a maximum depth allowable (manufacturer's maximum 40m) and it will positively not allow you to go deeper, even if you want to change your plan mid-dive or are just plain inattentive. You determine electronically where in the water column you want to be, using "position" mode. You enter on the display your chosen maximum depth and, having pressed the down button, it automatically stops you at that depth by putting air in your BC at the right moment and in the right amount.
     I first tried it set at 18m and managed to swim down to 22m before I was sent back, bobbing like a cork, to that depth.
     When you want to ascend to a shallower depth, you enter that figure and it puts air in your BC and raises you at the required safe ascent rate of less than 15m/min until you get there. It effectively turns your BC into a pneumatic elevator.
     You can ignore the programming and just use the "up" and "down" buttons. That's called "speed mode". I found I had to be careful not to help it by finning up, because that can get it all confused. In the same way, you must breathe in a normal and relaxed way. Erratically changing lung volumes seems to put it equally in disarray, especially at less than 6m.
     You must stay passive and let the BC do the work, controlled by the information from the handset and the parameters you set.
     The AquaPilot GF takes the form of a solenoid-triggered inflation valve and a similarly operated dump-valve that replaces the right shoulder dump-valve of your BC. You need the appropriate adapter. The valves are controlled by a rather large computer-operated handset that doubles as the air-integrated decompression computer.
     There is of course a manual dump on your BC that can be worked in combination with the normal direct-feed control in case things go pear-shaped during the dive, and a rip-cord will help you jettison the unit should the solenoid stick with the valve open.
     Two hoses connect to medium- and high-pressure ports on your regulator. Besides the air-integrated decompression computer, the unit uses high-pressure air fed to pneumatics activated by the electronic controller. Medium-pressure air is fed into the BC, in this case a pleasing Mares Synchro Power wing.
     The AquaPilot GF is designed for use with a wetsuit. The British importer tried to kid me that it worked equally well with a drysuit, provided it had an auto-dump. But if you use a drysuit correctly you will never need to put air in your BC.
     If you are neutrally buoyant at the surface in your drysuit and rig, you will need only to add air to make up for volume lost through the compression of that air in your suit as you go deeper. Your BC is merely there to hold your tank on your back and offer double redundancy in case your drysuit malfunctions. I really cannot see a sensible use for the AquaPilot in this instance, but I'm sure the importer will disagree.
     He was also keen to point out that this device was for all divers, and although it has obvious applications for those with certain disabilities, he is determined to market it to the wider audience. After all, as he says, cars with automatic gearboxes are not just for disabled drivers.
     Now I'm not sure this car analogy holds up. With auto transmission you just point the car and press the hot pedal. With the AquaPilot GF you have to keep entering in the depths you want to reach. That's all very well for UK square-profile dives, but you won't catch many divers with cash to spend doing these chilly dives in a wetsuit.
     My wetsuit diving involves multiple levels. It requires a lot of intermediate depths set between my deepest point and the surface. The AquaPilot is less than automatic in this case.
     Have you noticed that the most expensive sports cars are driven by elderly people? That's because it takes time to make money. And so it will be, I can assure you, with the AquaPilot. It will be those whose children have grown up and who, their mortgages paid off, can afford to lash out on such capriciously expensive ideas.
     That brings another problem. There are two types of people over 40, those who wear glasses and those who don't read. I can work the direct-feed hose and dump-valve of my BC with my eyes shut, and often have to. It's a very different business when I have to set figures on an LCD display. Quite frankly, my eyesight went bad when my assets came good, and here the display figures are not that big.
     Another thing: scuba-divers don't take to innovation readily. I would like to think I have supported all the innovations over the years that have proved worthy but I am never shy to slaughter a product that I consider does not work properly.
     The AquaPilot GF works perfectly and delivers everything it promises. But it is a complex and necessarily expensive item of kit designed to replace something we are already have, our eyes and our ears - and we still need our eyes to use it.
     At close to a grand, this will remain mainly the province of a few gadget-collectors and those determined to spend more money on their diving equipment than anyone else.
     It worked amazingly well, but I bothered with it only for a couple of dives before the novelty wore off. If you have problems with buoyancy control, you would be better off spending a fraction of the cost on learning buoyancy skills from a good instructor.
     The AquaPilot GF costs £980 including charger and PC software.

Avoid the bean-bag look
THERE WAS A TIME WHEN I HAD the physique of an Adonis, when other men admired me and young women cluttered the path to my door. In my dreams, of course. It's just that now I have reached the point at which other, younger, people comment that I look good for my age. And I'm only 34!
     Of course, being blessed with the body of a skinny git means that I can now offer advice to all those men who had 52in chests but have since acquired 52in waists to match on how they can get fit like me. Luckily none has yet thought to apply their excess weight behind a straight left! The worst I have received is the unwanted adulation of Basil Fawlty fans.
     But we all worry about what we look like when we take our clothes off. It's OK when covered with a thick layer of neoprene but there comes a time when such a heavy layer of insulation is not needed and the more courageous or foolhardy don the lycra dive-skin.
     For those who have been incautious with intake of beer and crisps since making the school football team, this garment can impart a particular and ill-judged sense of well-being. They might think they look good but usually they look like an old bean-bag cushion on which the stuffing needs rearrangement.
     I usually reflect when confronted by such sights that diving will never catch on as a poser's sport, as skiing has.
     So what to wear? Enter Oceanic with the Cyberskin, a neoprene suit with all the characteristics for calming contours and yet constructed of material only 0.5mm thick. It's a one-piece suit with a zip typically positioned at the back and loops under the heels as on ski-pants to stop it riding up.
     I found it ideal for use when snorkelling in warm water. It added little buoyancy, so I could still duck-dive easily without the help of weights, and it dried off quickly too.
The Oceanic Cyberskin costs £65.

Light years from the Manta
"AMONG SERIOUS PROFESSIONAL AND MILITARY DIVERS, Apeks is renowned as a manufacturer of superior high-performance breathing regulators." So reads the Apeks brochure.
     This might be the case today, but it was not always so. It seems only yesterday that Apeks supplemented a lacklustre side-exhaust regulator called the Manta with a new conventional-format model called the T50, which surprised everyone by being a world-beater.
     Apeks went on to develop the T50D and then a whole raft of new dry-sealed diaphragm regulators including the TX40, TX50 and, most recently, the TX100. They have all proved to be world-leading performers among regulators and, I'm proud to say, they are British.
     It was easy to make something better than the Manta. It had all the breathing characteristics of a drowning asthmatic being strangled. The problem today for Apeks must be to manufacture something better than its top-of-the-range TX100.
     The only criticism levelled at all these regulators now is that the second stages are rather large compared to some available from other manufacturers. To meet this challenge, Apeks has produced the Advanced TX range. There is an ATX40, ATX50 and an ATX100, not forgetting the AT20 warmwater regulator.
     Each has the same first stage as on its TX and T counterparts but comes with a new lightweight and smaller second stage.
     The top model, the Apeks ATX200, has an entirely new first stage. This is stubbier than that of the TX100 and has the look of the TX50s, but instead of having a turret, like the TX100, it has fixed ports. The over-riding difference is the unusual shiny black chrome finish.
     Underneath there is a removable valve seat and the model follows the Apeks successful dry-sealed formula, ideal for use in cold and contaminated water. It can handle pressures of up to 350 bar in DIN-connector form. There are four medium-pressure and two high-pressure ports. Though compact, this is a weighty item.
     The ATX200 second stage, in common with all the other ATX second stages, is not as minuscule as some others now appearing or about to appear in dive shops, but is appreciably smaller than its predecessor.
     It has the same side-knob that enables the user to turn up the cracking pressure, the effort to initially open the valve, and a venturi lever which positions a disrupting vane in the air-flow to discourage exponential free-flows when you first pass from air to water.
     There is also the familiar heat-exchanger at the junction between second stage and hose that will impart a little of what heat there might be in the water to the very cold air coming from the first stage.
     The ability of ambient water pressure to make its presence felt instantly on the outer side of the diaphragm of the second stage affects the ultimate performance of the regulator. This is why the designers rejected the idea of a very small frontal area. The slots that let the water pass are as big as those on any regulator.
     Behind them there appears to be a second heat-exchanger of mirror-polished metal. The exhaust port is nicely injection-moulded in one piece with the rest of the unit and has a concave inner surface, thoughtfully designed where it rests on the diver's chin.
     To aid with servicing, these ATX second stages have a micro-adjustment built in, so that technicians can adjust each regulator precisely to give optimum performance without having to strip the unit down.
     An added bonus for customers is that instead of getting a mouthpiece that might not appeal to them, Apeks includes a choice of two different types with every regulator it sells.
     So what was it like at depth? It breathed like a dream! A dry one! But is it really worth the extra cost compared to the £239 ATX40? You must decide.
     The Apeks ATX200 costs £364 while the Stage 3 set, complete with alternative octopus-rig ATX40 second stage, costs £482.

ON A WING AND A SPARE
Regular readers of these pages will know that although I am not a great fan of most BCs from AP Valves, one of my favourite of all time is the Buddy Trident (formerly Tri-mix), a wing design with a couple of side-pockets and a single, very accessible front pouch with two pockets.
     You might also know my predilection for Buddy Twinning Bands (and Blocks) which enable me to twin up any pair of independent cylinders, wherever I am. The twinning bands work with any BC with the required four slots for cambands, but work especially well with the Trident or any other Buddy BC.
     The Trident wing provides 22kg of lift, ample when used with aluminium cylinders. However, my visit to Bikini atoll found me using much heavier twin steel cylinders.
     Aluminium cylinders are heavy out of the water but light in it, so you need to add more weights with a twinset than with a single cylinder.
     Steel cylinders weigh a lot even when immersed, so you can do without a weightbelt with steel twins.
     As I would be using a wetsuit rather than a drysuit, the matter of redundant buoyancy raised its head. What would I do if the Trident's internal bag failed? It has been known to happen, even with robust Buddy products. With no weightbelt to drop, trying to decide whether it would be better to keep breathing or dump my tanks while plunging downwards is not a choice I want to have to make. So I got on to AP Valves and the company sent me a Buddy Redwing to add to the Trident.
     The Redwing has a buoyancy bag exactly the same as that fitted to the harness of the Trident. Like all Buddy BCs, it is of a tough double-bag construction. The Redwing simply threads through with the same cambands and is sandwiched between the BC and the tank. The only difference is that the corrugated hose has a pull-dump and is mounted on the opposite side, the right. This makes it easy to connect its direct-feed hose to a second regulator first stage, thereby providing total redundancy.
     It provides identical lift to the Trident but you should need to use it only if you encounter a catastrophic failure of the main BC, or if for some reason your primary regulator fails during the dive and you need to switch to your second (ask my friend Jim about that!). What you do not do is use the two to provide 44kg of lift as a routine procedure.
     The combination of Redwing and primary BC looks a little bulky when compared to those technical BCs which have two buoyancy bags contained within a single outer cover, but it does offer the typical Buddy construction values that some call "unbustability".
The Redwing costs £160 and cannot be used alone.