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.

Back in 1998, we at Diver did a regulator comparison test which left the people at certain manufacturers smarting from the exposure.
     Some sent lawyers' letters threatening me with bankruptcy and worse, but Cressi-sub, a company that was dismayed to hear that one of its sample regulators had failed to get to 50m on the ANSTI machine, invited me to visit its factory in Genoa to enjoy the hospitality of Antonio Cressi and his family.
     There were some back home who thought that I would, at best, wake up with Bernard Eaton's head in my bed. Others suggested I should go wearing something suitable for a funeral.
     However, well-travelled as I am, I was not going to confuse the gentlemanly northern Italians with any Corleone capos. I set off full of confidence.
     Naturally, during the initial moments of my visit, some of the lower management made impassioned pleas to me about the need to feed their families. However, during my first formal meeting with Mr Cressi, I was allowed to make my case for an independent opinion.
     I told a shocked audience that, while I believed that Cressi-sub made a lot of rather fine products, its regulators could not be numbered among them.
     Mr Cressi listened patiently to what I had to say, then calmly turned to his assembled lieutenants and stated that if that was the situation, and these were the findings of Diver Magazine, then Cressi-sub would simply have to make a better regulator.
     The Cressi AirTech is it.
     Gone is the rather old-fashioned, tall-turret, piston first stage. In its place there is a compact diaphragm design that can be fitted with a dry-sealed coldwater kit should you require it.
     The four medium-pressure and two high-pressure ports that we now come to expect on top-of-the-range regulators are arranged around a tapered barrel, reminiscent of that of the Aqua-Lung Titan, and that means the hoses get routed just where you want them.
     Instead of that toy-like second stage made of shiny plastic, there is now a business-like effort, pneumatically balanced, in matt-black plastic with rubber and titanium inserts.
     The front face unscrews in a satisfying way to reveal the heat-exchanger, which is positioned at the point where the hose meets the regulator. This extends, with a large vane, well into the breathing chamber.
     The venturi ± switch operates another vane positioned directly in the path of the air that comes from the air-jet facing directly into the user's mouth. It's a very effective arrangement.
     A representative of another manufacturer recently remarked to me that no regulator-maker wanted buyers unscrewing the fronts of their expensive purchases and discovering that they contained little to impress them!
     Cressi has no worries in this case. I was also able to put the thing back together properly in a moment, neither cursing nor searching for tiny locking-pins, so if you do accidentally drag this regulator in the sand, it will be a simple matter to clean out any grit.
     The AirTech, in common with most other top-range regulators, has a breathing-resistance adjustment knob. Everyone seems to want them, though I see no point in them and left it set at minimum effort.
     However, this one is well-engineered and has an easy-to-grip knob that takes lots of turns from ÒMinÓ to ÒMaxÓ. I am sure some buyers will enjoy happy hours under water fiddling with theirs.
     The unit is quite large compared to some of the mini-sized second stages available these days, and the mouthpiece is fairly soft and positions the exhaust port well forward of the chin.
     This means that the AirTech second stage feels relatively heavy in the mouth when tried in the dive store, though I found no trace of this effect in the water.
     However, I wondered why the designers had not made the rigid plastic casting for the exhaust port more like that of the Apeks ATX range, so that it sits on your chin.
     In the water, the AirTech breathed faultlessly and I used it deep and in strong currents.
     Well done, Antonio! Well done, the men of Cressi-sub! Welcome to the first division of the regulator market.
     What a pity it did not arrive in time for our recent mid-price regulator comparison - it would have been a contender!
The AirTech costs £275, or £299 with dry-sealed coldwater kit.

Who needs a box on wheels?
There are times when you could really do with a trolley. The Diver's Companion is one designed specifically to carry your dive kit and cylinder.
     An ABS box fits on to a substantial stainless-steel trolley which has additional castors so that it can be operated flat as well as like a sack-truck. The cylinder is sandwiched between box and trolley, secured by bungee cords. The box has cam-catches that can be fitted with padlocks.
     The Diver's Companion is a complex solution to a problem that I'm not sure exists.
     This is not for divers who travel by train or plane. Rail staff won't want to carry it, complete with dangerous-looking cylinder, in the guard's van, and in the case of air-travel, it weighs a ton before you start loading it.
     Divers who travel to a dive site by car put everything in the boot and walk fully kitted to the water's edge. Why would you need a box?
     There is no way you could put the Diver's Companion directly into your car - you would need to break it down into box, cylinder and trolley before loading it, unless you have a big vehicle equipped with a tail-lift.
     If you're going on a hardboat you might feel clever rolling your Diver's Companion down the jetty - until the skipper asks where you think you're going to stow the thing. Wheeled items develop a life of their own on the rolling decks of boats, even if the castors do have locking brakes.
     It might come in useful at, say, Swanage, if you had to park far from the pier, or at Stoney Cove when the upper car-park is full. The main wheels are big and will roll over fairly rough ground. But what do you do with it once you've kitted up? Roll it back to your car, while wearing your kit? Or leave it where it is, to be vandalised or stolen?
     It could be handy for transporting your kit from car to pool on club nights, or for Dive Show exhibitors coming in loaded from a far-off car-park. And it might appeal if you live within walking distance of the dive-site, but then your buddy will need a Diver's Companion too.
     Most dive bags have rucksack straps and wheels, so I have a feeling you might do better saving the cost of the Diver's Companion, pooling your resources and buying a secondhand van.
The Diver's Companion costs £350.

Every which way but one!
Now that Suunto has taken over the world of diving computers with its menu-driven models, the other manufacturers have rushed back to the drawing board to devise something similar.
     That includes Oceanic, the US company that probably has the lion's share of its enormous home market. Its Versa Pro is a two-button, menu-driven, nitrox computer that complements the Versa, a cheaper, air-only, entry-level model.
     Oceanic has gone out of its way to offer every diving computer ingredient - with one exception, which I will come to later.
     It is operated by two buttons, and unlike previous Oceanic computers it is also water-activated, so no more forgetting to switch it on before diving! The buttons allow two groups of options to be set.
     First are those you might set on a dive-to-dive basis, such as nitrox mix and maximum-depth alarm. Second are those you might set once and never alter, such as measurements in metric or imperial, or the date and time.
     The thinking behind the design of the Versa Pro is all about these user-options and I counted at least 14 different ones, including the option to turn the water-activation feature off! There are tissue-loading and oxygen-accumulation bar graphs, and a variable ascent-rate indicator. You can choose whether you prefer the simplest amount of information, such as actual depth and remaining no-stop time, or whether to press a button during the dive and have this augmented by dive time and maximum depth achieved.
     In decompression-stop diving mode, the computer has four different displays that can be brought up at will, and between them they dispense an awful lot of information.
     You have the option to set a terrifying number of alarms, too. An innovative feature is the red light that comes on when an alarm is triggered, very useful on night dives or in low visibility.
     The Versa Pro is straightforward to understand, thanks to its well-structured instruction manual, and has a dive-simulator mode that allows you to become familiar with it before you reach the water.
     The display is big, well-lit and easily read. The Versa Pro looks great in its brushed aluminium and thermoplastic finish. It has a removable Perspex shield to protect its screen and it has a great strap. All in all, it's a very desirable piece of kit, apart from that one exception, the clue to which lies in the Safety and Reference Manual provided alongside its instructions.
     Page seven of this states: ÒThe decompression model used by an Oceanic dive computer is based on the no-decompression multi-level repetitive dive schedules successfully tested by Dr Ray Rogers and Dr Michael Powell. These tests did not include dives deeper than 90 feet (27m) or decompression (stop) dives.Ó
     Decompression-stop dives are the type of dives I commonly do, and I took the Versa Pro on a series of 12 such dives (many repetitive) alongside a Cressi Archimede and a Suunto Vytec.
     Only once did the Oceanic momentarily show me entering deco-mode, though the other two had me into deco-mode on nearly every dive.
     Not only that, but the discrepancy between the amount of no-stop time remaining on the Oceanic Versa and the deco-stops demanded by the other two was alarming.
     A diver has to rely on the deco information provided by a computer. You can never tell how close you come to getting bent. Some might say that the Suunto RGBM100 model is far too cautious. Many different computers on the market, including the Cressi, use the readily available Buhlmann ZH-L16 model.
     They might all be wrong and the Oceanic right. I can't tell you.
     However, I can state that there were times on dives when the Suunto and Cressi were showing the first stop at 3m while the Oceanic Versa Pro showed 45 minutes of no-stop time remaining.
     On one particular 38m dive, the Suunto showed eight minutes and the Cressi five minutes of total ascent time needed, while the Versa Pro still showed 15 minutes of no-stop time remaining.
     On the last notable occasion towards the end of my trip, when I still had the three computers side-by-side, I did two consecutive dives, one to 42m and the second to 32m, with only a one-hour interval. At the time I began my ascent, the Suunto showed 18 minutes and the Cressi 10 minutes of total ascent-time, while the Oceanic Versa Pro was still displaying plenty of no-stop time remaining.
     So who is this computer for? Surely it's not merely for those who do short shallow dives well within normal no-deco limits?
     Could it be for those vacation divers who never go past 27m and never stay in long enough really to need a computer? If you think long stops are boring and unnecessary, the Oceanic Versa Pro will suit you.
The Oceanic Versa Pro costs £299 and the air-only Versa costs £185.

Getting heavy with lights
Bang! Bang! Bang! The noise startled everyone. It was Wally Lumb, GreenForce UK distributor, demonstrating the resilience of the Belgian-made Impact 100 HID umbilical diving light by repeatedly smashing it on to a wooden block.
     Brutish his demonstration might have been, but it was probably the most exciting thing that happened at this year's SITA British diving trade-show held in Chelsea FC's stadium. I bet chairman Ken Bates, up in his office, was irritated by the sound! I know everyone else was.
     It seems that while HID (High Intensity Discharge) lamps can deliver extra brightness, many were arriving back with their distributors like so many homing pigeons. They were proving too fragile in the rigorous world of divers.
     GreenForce believes its Impact HID is the answer. Its products are made with anodised aluminium but two extra chemical treatments give them a hard, green-looking protective coating.
     Each component is part of a system that allows the user the freedom to assemble it in the way that suits him best. You can screw any one of seven different lampheads directly into a selection of nickel-metal hydride battery packs, or opt for an umbilical cable and mount the battery pack on your tank or elsewhere.
     Connections are protected by three in-line O-rings. A selection of different handles is available, so one man's GreenForce lamp looks very different from the next. You can also choose between a six-hour fast charger and a normal 12-hour charger.
     The Impact 100 HID is a lot bigger than any of the other lampheads, so I opted to use the umbilical connection and mount the fat G1 Ni-Mh battery pack on my tank by means of a Lumb Bros pony clamp and mounting bracket, removing the battery pack handle so that there was no danger of snagging. A Lumb band and No 2 snap hook attachment was used to clip the lamphead conveniently to a D-ring on my BC. The lamphead's large size did not prove to be a problem under water.
     An HID lamp gives out a great deal of light for its size and voltage, and of a higher colour temperature than conventional tungsten lamps, which burn at between 2700ûK and 3300ûK.
     Daylight is 5500ûK but the GreenForce appears to burn at 6200ûK, rather cold and unsympathetic to the things it illuminates. However, the higher the colour temperature or the bluer the light, the further it penetrates in water.
     An HID lamp needs time to warm up, which precludes switching it on and off - lucky in this case, as there is no switch. You simply screw in the plug connection until contact is made.
     That's fine for turning on but I wouldn't trust a lot of divers to turn it off this way while under water, because it could be unscrewed too far and flood the unit. It's best to leave it on.
     Ni-Mh batteries can be topped up at any time without damage, but they do give off gas, so I was pleased to see that a gas-vent valve was included in the design of the battery pack. Burntime for a fully charged unit with the G1 battery pack is certainly more than the 50 minutes I enjoyed on each dive.
     The reflector unscrews to adjust the beam-width, protected by three O-rings in line. Again there is a risk that the heavy-handed could flood the unit by unscrewing it too far, so I suggest pre-adjusting it to suit your taste and leaving it set.
     I found that the beam could be adjusted to make it fairly even, though not enough for use as a video light. The unit sent for test had evidently already been in far less sympathetic hands than mine and looked quite shabby even before I started.
     However, it continued to work despite being bounced around the deck of various speeding small boats and in luggage loaded on and off numerous planes during an extended trip in the Pacific.
The GreenForce Impact 100 HID as tested costs £577. The Lumb pony bracket is £40 and the Lumb No2 snap hook attachment £15 extra.