Uwatec, the Swiss diving computer company, has certainly made an impression on the market with its Buhlmann ZH-L8-ADT programme. It is now used in all the Aladin computers and siblings sold under other brand names.
At the same time, the company's Aladin Air X, featuring air integration using a radio transmitter from the regulator 1st stage, has provided the safety advantages of including remaining air-time in the display and including relative air consumption in the decompression calculations - at a price premium of course.
Readers should be reminded that the Air X automatically takes into account the diver's workload, based on his breathing rate during the dive. Other computers which take into account workload invariably need the information pre-programmed into them prior to the dive, with the aid of a PC, a suitable interface and software package.
Now that Uwatec (pronounced 'oovertek') is firmly into the new wave of nitrox diving with its marketing of the Draeger Atlantis rebreather, it's no surprise to find that it has produced a nitrox version of its top of the range offering, unsurprisingly called the Aladin Air X Nitrox.
Naturally, it does everything te standard Aladin Air X and its clones do (Diver November 1994, March 1995 and October 1995). It can be distinguished by the blue rather than black anatomically-shaped casing of the wrist unit. The transmitter unit appears to be the same and, obviously, its O-ring is nitrox-compatible.
In addition to the decompression work of Uwatec and Dynatron with Prof Buhlmann, this computer has a CNS clock model by Dr Bill Hamilton. This takes care of oxygen toxicity tracking, and the CNS O2 clock is linked to the breathing rate of the diver and consequently his workload.
This feature is shown in a CNS exposure percentage display and audible alarm should you approach the limit. The limit warning can be adjusted to sound at the chosen CNS exposure percentage (from 75 per cent) by those who have the Aladin Datatrak interface and software for use with a PC.
The oxygen mix is user-adjustable for air (21 per cent oxygen) and from 22 per cent to 50 per cent in increments of 2 per cent. This is displayed on the screen. Decompression requirements are adjusted taking into account the residual percentage of nitrogen.
There is also an audible alarm which sounds in the event of reaching the ppO2 depth limit. Again, those with Datatrak can adjust the point at which this sounds. The current depth display will also pulse when the ppO2 limit is being exceeded.
Other audible dive mode attention messages include remaining breathing time of less than 3 minutes, end of no-stop diving phase, and interruption of, or loss of, tank data reception and remaining breathing time calculation. These are single 'beeps'.
While under water, continuous 'beeps' signal alarm messages. These sound for an excessive ascent rate, ignoring a required decompression stop, remaining breathing time at zero, battery low, and CNS oxygen toxicity limit reached (again this is user adjustable and calibrations start at 75 per cent of the maximum).
Once you have set your oxygen percentage, it stays permanently in the computer until you change it. This is not the case with every nitrox computer. However, if you change mixes between dives, it's down to you to tell the computer.
I even managed to get the CNS warning to display 100 per cent when I omitted to reset the computer after doing one dive on nitrox 50 (with a rebreather), before doing another dive on nitrox 28 with ordinary open-circuit scuba. It did give me the opportunity to hear all the alarms as I passed 20m without risk to my health. Luckily, I was doubling up with an ordinary air computer which took care of my decompression status.
To a non nitrox-trained diver, this may all sound terribly complicated. However, I can assure you I am not a very clever bear and yet I managed to grasp an understanding of the acceptable level of ppO2 as a nitrox trainee and found that the Aladin Air X Nitrox was very user friendly and easy to understand under water. The price, however, is more difficult - £790.
I took the opportunity to test both a new drysuit and a new drysuit diver when I took Jonty Summers, a recently qualified diver and colleague at Diver, and an Otter Hammerhead drysuit for Jonty's first drysuit dive, at Stoney Cove.
We equipped him with the new front-entry Hammerhead, a membrane suit, supplied in an off-the-peg size. It's made of a fabric called Otterskin, a light, tri-laminate composite material, which the manufacturer has tested extensively for durability. The material is also slightly stretchy which gives the suit added comfort.
The six main sections are beautifully stitched and glued, with the inner side of the seams well taped over with latex. Latex seals are provided at neck and cuffs, with the cuff seals being of extra heavy duty material. An alternative neoprene neck seal is optional.
The tri-laminate material is double layered over the lower leg areas at the front to form an extra durable area in lieu of knee-pads. There's a large pocket mounted in front of the left knee.
The extra long diagonal front zip starts low down at the right hip and crosses well over the left shoulder. It's immaculately taped in, with a reinforcement of soft trimming on the outside to give it a high quality finish. Apeks constant-volume shoulder dump and direct feed valves are fitted, with an additional layer of rubber in the sandwich between the inner and outer parts of the valve.
Jonty's version of the suit came with the ubiquitous Scottish-made wellies. Never before having tried a drysuit, he was pleased to discover that these wellies are lightweight and not at all like the type you'd wear on land. Boots of dipped neoprene are also an option.
The suit was supplied with both neoprene socks and Thinsulate ones. Jonty opted for the neoprene ones as it was a warm day. Also in the kitbag, which accompanied the suit, there was a very nice Thinsulate undersuit, and a neoprene hood.
Jonty found the whole package very easy to don and was ready to dive in no time at all. After a quarry-side briefing on how to work the valves correctly, he was ready to go. He had a very comfortable dive, uneventful gear-wise, and came back totally dry on the inside. What more can anyone want from a drysuit?
Though lightweight, the Otterskin material looks to be very hard-wearing. The Hammerhead suit is also available in a traditional cross-shoulder zip configuration, in which case it enjoys an additional knee pocket.
Complete kits including suit, undersuit, hood, socks, valves, direct-feed hose, and kit-bag start from around £500. The tri-laminate suit alone costs from £290. Hammerhead suits in both front and shoulder-entry versions are available in a range of 16 men's and 10 women's sizes, plus made-to-measure.
I'm always suspicious of any consumer durable bearing the legend 'Pro'. We commonly see it on video cameras, stereos, and sports equipment. Ironically, it usually means it's intended for amateurs - but then we are all amateur divers, aren't we?
Aquion's Pro Elite drysuit is the latest in its range of membrane drysuits. It is a tough suit, constructed using multiple sections of a hard wearing tri-laminate material, stitched, glued and taped together. It will appeal to the British club diver who wants value for money through longevity, but who is perhaps prepared to forego a little in the style department.
Aquion uses a range of 12 bright colours (plus black), and since the suit is made from so many panels, an unusual 'Joseph's coat' effect can easily be achieved by choosing the multi-colour (5 or more) option. There are some divers who, unable to settle on a particular colour scheme (like the creators of some middle-European national costumes), choose to use them all!
Other options include a slate pocket, a knife sheath pocket, a convenience zip, heavy-duty shoulder pads, knee pads, boots, and neoprene or latex hoods. Aquion also offers a made-to-measure service. All the options together can add close on an extra 400 to the cost of the suit.
We tried an off-the-peg one which came with latex neck and wrist seals, and rather natty neoprene boots which my test buddy reported as being rather comfortable. These had interesting protrusions on the heel - highly effective in discouraging fin straps from slipping off.
The raglan cut to the sleeves, with sleeve material let in from the hip, allows for plenty of unrestricted arm movement and eliminates stress points. The bodice is securely joined to the lower torso and legs by a reinforced section in a contrasting colour material.
The material is doubled up in a similar way to create reinforced knee pads which have small holes for draining. These invariably solicit a laugh on climbing back into the boat after a dive, as water hoses out from them in a way that mimics a punctured and flooded suit. The suit had a standard Apeks direct feed valve at the chest and an Apeks adjustable auto-dump valve on the left shoulder. It's possible to obtain the suit without valves, and a cuff dump is also available.
It also had a cross shoulder dry-zip for what is unusually called a 'rear entry' version of the suit! Front entry suits with diagonal zips are also available.
Built-in braces made the suit more comfortable and were essential in preventing the sag which causes the 'dustbin liner' look. Uniquely, there is a large panel of neoprene let into the back section of the tri-laminate design. This allows the suit to be slightly tighter and more fitting than you might otherwise have chosen. This padded panel stretches in two ways, making for additional comfort, allowing the suit to move when you do.
Complete with carrying sack, the Aquion Pro Elite costs £640 in the form in which we tested it.
It was rather refreshing to be asked to try the Mares Vector Pro BCD after using what seemed like a plethora of new designs for 'tekkies'. The Vector Pro is what I may now call 'a good old fashioned stab-jacket'.
It's a single-bag design with a rigid backpack and curved hip support. It's secured to the cylinder by means of a single cam-band. Air is supplied via the normal direct feed, which clips neatly to a corrugated hose. The control has a pleasant anatomical feel to it, with a rubber mouthpiece to which your lips won't stick if filling orally! Air can be dumped by pulling on the hose and operating the shoulder dump valve. There's also a bottom-of-the-bag dump valve, operated by a pull-cord.
The front shoulder straps have chunky, quick-release buckles, and there's a wide Velcro-laden cummerbund at the waist. The front parts of the BC (those which bear the pockets) are held closed by two smaller straps with quick release buckles at the lower chest.
The whole thing is finished in a heavyweight material, which feels as if it might last well. As a finishing touch, two hose clips and a clip-on whistle have been added. For traditional BSAC divers, there's also a 0.4 litre add-on air bottle option.
In the large version, which I wore, there was more than 19kg of lift when fully inflated. (This maximum lift ranges up to 22kg in the XL size.) Most of this lift was under the arms which gave a comfortable armchair-like support when waiting for the boat at the surface.
In the water, there was little more to say, save that with a jacket of this type it is important to have one which fits correctly. Choose the right size! The Mares Vector Pro is available in XS, S, M, L, and XL, price £ 275.
The Diver's Heliograph signal mirror is a cunning device. The idea is that you view your target (the boat or shore party) through the hole in the mirror and the sighting device (which has a similar hole). Once the two are aligned, the diver angles the mirror so that you see the white plastic material of the sight lit by the sun. This ensures that the sun is reflected towards the target audience. I tried it in the calm, sunny waters of the Maldives. Provided the sun was between me and the boat, people in the boat reported seeing me twinkling!
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