DIVER TESTS

November 1996


Sweet and dry
John Bantin was resigned to being a headless hunchback until he found a suit that proved both tough and flexible
Aqua-flex dry suit The AQUA-FLEX drysuit is the top-of-the-line offering from Aqualeisure, a company based in Wales that has been exporting suits to Europe for about seven years. It is well-known for surface drysuits and canoeing equipment.
The Aqua-Flex is a very lightweight suit made from a tri-laminate of butyl in a polyester sandwich, the kneepads reinforced with a double layer of the material. This 410g grade fabric was originally developed for special military forces to use in chemical warfare situations, so it should be strong enough even for British diving conditions.
Despite my every effort, the suit proved resistant to hard use. The flexibility of the material is reflected in the degree of comfort it affords the wearer. The eight main sections of material are double-stitched and double-seamed, with all gluing cold-taped for longevity.
The suit I was sent fitted me perfectly, although I was dismayed at first when I saw that it came with a diagonal front-entry zip.
I usually find these self-donning designs difficult to put on. I am extremely tall, and the manufacturers rarely leave enough give in the torso to allow me to reach back and pull the upper part over my head. The result is to turn me into a headless hunchback, running round, sweating profusely and calling for assistance.
This must be where the flexibility of the Aqua-Flex suit's material comes in, because (surprise, surprise) it was all very easy. As usual, because the zip went over my shoulder, I still needed help to get it started. Once fastened, the zip is hidden by a flap of material that is itself held closed by Velcro.
Internal adjustable braces are provided to stop the suit bagging at the crotch. Latex seals at neck and wrist add to the high degree of comfort. The lack of insulation afforded by thin latex at the nape of the neck, and the localised cold feeling it imparted underwater, often led me to believe that the suit was leaking. However, it was not.
I am told that neoprene seals are an option but I prefer the better watertight characteristics of latex and would opt to wear a thin woollen scarf round my lower neck - under the suit of course!
The Aqua-Flex suit is finished off with comfortable rubber boots.
There is a choice of valves but the suit I tried came with a SI Tech low-profile, constant-volume dump. This was less liable to get hooked up on the shoulder-straps of my BC than a more conventional design when I was getting ready to dive, and worked automatically on ascent.
The centre chest inflation valve was also by SI Tech. The Swedish company has long experience of making suit valves and developed the first auto dump for Viking suits about 20 years ago.
The Aqua-Tech suit is available in black, grey, yellow, orange or plum. Contrasting kneepads come in red, blue, yellow, pink or mauve.
Aqualeisure sent an attractive tartan 100g thinsulate for use with the Aqua-Flex suit, and this proved quite warm enough on some long dives in British waters. It had a generous polyester fleece lining, and was elasticated at the back of the waist, and at neck and cuffs.
In contrast to many undersuits I have tried, the foot straps did not tear off. The full kit price, for the suit fitted with auto dump valve, thinsulate, bag and hose, is £500. Eleven sizes are available off-the-peg, or you can use the made-to-measure service, as I did.
Achilles heel on flying fins
Zeagle's Raptor fins Diving equipment looks more serious every day. I have just tried some fearsome-looking fins from Zeagle called "Raptor". They were too big to get in my normally capacious dive bag and aroused a lot of interest with the other occupants of the dive boats on which I later found myself. The fins are finished in "technical diver" black and mine came with a foot-pocket big enough for the largest drysuit boot and extending the full length of the foot. The enormously long fin blades culminated in a thickened section with a profile very like a section through an aircraft's wing. Unballasted the fins were slightly positively buoyant, but by unscrewing the side panels you can transfer weight to the fin-tips from elsewhere in your equipment configuration, by means of suitably small packets of lead shot.
The fin blades have a rigid centre section but the outer chassis is allowed to flex. In the water, the effect is to build up a powerful pendulum-like rhythm to one's finning action that appeared to make it easy to swim long distances in what seemed to be an "unstoppable" manner! It seemed ideal for the diver loaded down with innumerable tanks.
It was difficult to quantify acceleration but even I, not famed for my athleticism under water, found that I was overtaking divers with whom I would not normally bother to try to keep up.
However, that was over the straight and on those long sweeping A-road equivalents found along the faces of extensive Egyptian Red Sea reef walls. Once I got into the tight cornering needed within the confines of wrecks, or when trying to manoeuvre with a camera, the long blades proved unhelpful. It was like trying to drive a Lamborghini Countach in town.
Normally I tend to loll about in the water, watching the world go by. With the Raptors, I soon found myself buddied with someone who used a pair of those ridiculously long free-diving fins for scuba and whose idea of a dive was to get his head down and cover as great a distance as possible (he spent his surface time in the gym).
I cannot say I saw much while using the Raptors; everything was a blur! But I used them for a number of dives and despite covering large distances at high speed, I always returned to the boat fit and relaxed.
Sadly, the stresses and strains of all this action had to be paid for somewhere, and by the fourth dive the very normal-looking plastic quick-release buckles (probably Taiwan's best) revealed their weakness. One snapped as I was pulling the strap over my heel, just as I was about to enter the water.
Because we "technical divers" put our fins on only when finally loaded down with several tons of redundant equipment plus more tanks than most dive shops bother to stock, the Raptor buckle's little roller, "pinging" out across the deck, could have been the last straw. The roll of the boat meant I had to keep my grip on everything including my temper while a helpful crewman swapped the now unusable Raptors for my normal-length Italian jobs.
At least they hadn't broken during the dive, but when I got back I contacted DUI, Zeagle's importers, and reported my findings. They tell me they will be looking into matters and will be sure to supply a buckle sufficiently robust in future.
Meanwhile I suggest that if you wish to buy a pair of these otherwise excellent fins, you examine the plastic buckle and satisfy yourself that the structure is strong enough to withstand the forces likely to be applied to the strap and the roller past which it is threaded. And carry a spare pair.
Zeagle Raptors come in four sizes and cost £140.
Talking of fin buckles...
You have to hand it to the Italian company Mares. After years in th doldrums with some lacklustre products, it has recently got its act together and produced some remarkable ones.
Its Plana Avanti fins took the diving world by storm. Then, when the competition looked to be closing, Mares simply moved up a gear with the Plana Avanti Quattros.
The original Avantis were probably the first fins to be fitted with Fastex-style buckles on their straps for quick release. Now that every other fin manufacturer has adopted this design, Mares has looked to see how it could improve on it.
Fastex buckles are good for releasing foot from strap but hard to reconnect if that strap is under tension. The latest Mares fins come with an entirely different design of buckle which reminded me of that on a ski-boot, in that it uses a lever action as being easily releasable.
We have come a long way since all fins had a rubber strap threaded round a bit of bent metal, but I was interested to see whether these new buckles would perform as well when diving as they did in the dive shop.
I am pleased to report that they survived a week's hard abuse, diving twice a day. We will have to wait to see if they last as long as the bent metal of my first black rubber fins. The new buckles are fitted to Mares Avanti, Quattro Avanti, and Power Plana fins.
Bubbly regs for fun diving
Sherwood regulator Sherwood regulators had never been marketed efficiently in this country until Sherwood UK Ltd was set up. The brand is well-known in many other parts of the world, including the USA. The names of the latest Sherwood SRB5300 Magnum and SRB5100 Brut give a clue as to what they're all about. In champagne terms, "brut" means extra dry, and a "magnum" has twice the capacity of a bottle.
In each case the first stage is a flow-by piston design with the unique Sherwood patent "dry bleed" feature. This keeps the works dry by maintaining them under positive air pressure over the surrounding water, a way of dealing with cold or contaminated water. Excess air is bled off as a minute stream of bubbles from a one-way valve positioned alongside the medium-pressure ports. Be warned that this can give rise to ill-informed dive buddies telling the user that a tank O-ring is about to break!
The Magnum has a balanced first stage. It has four mp and two hp ports.
I have suffered a problem with this brand of regulator in the past because the first-stage A-clamps seemed specifically made for use with standard American tank valves. The flange that marries to the tank O-ring was insufficiently deep to make a good seal with those DIN tanks that have an international A-clamp conversion insert screwed into them. (See our review of regulators in the May and June issues of Diver.)
I am pleased to say that the newly designed first stages gave no hint of this problem during a visit to Egypt, where a great variety of cylinder valve types seem to be used.
In both the Magnum and Brut, the second stage is a sweet little affair, with a small diaphragm set in an oval unit. The mouthpiece is a long design that I found sat well back between my molars, eliminating jaw-fatigue without any tendency to make me gag!
The compact exhaust port did not appear to direct my exhaled bubbles close to my face in the annoying way I might have expected, either.
The unbalanced Brut, possibly thought of more as an octopus rig because it comes with a slightly longer mp hose, gave an easy breathe while the tank was full. When compared directly with the vastly more expensive Italian regulator mounted on the other tank of my twin-set at the time, I noted that the Brut's breathing-resistance increased noticeably while pulling out the last 50 bar of air. This revealed the disadvantage of an unbalanced valve design.
The Brut's first stage also differs from the Magnum in having only one hp alongside its four mp ports. If you are a serious diver who spends a lot of time working hard at depth or in Welsh mountain quarries in winter, the Brut is probably not a good choice of regulator for you. The apparently poor heatsink characteristics of the second stage seem to indicate the same about the Magnum so I was surprised to see that Sherwood had achieved EN250 Cold Water test certification for both model. If you dive simply for relaxation and fun, these two regulators are certainly worth considering. Their small second stages make them comfortable to use and they could become a favourite for the models of underwater photographers. They come in a choice of coloured fronts.
The Sherwood SRB5300 Magnum costs £170, the SRB5100 Brut £134.
What's in a cylinder?
Divex Mini O2 AnalyserThe only part of nitrox diving that might be considered complicated is the need to analyse the contents of your aqualung cylinder immediately before using it. So every nitrox diver (or group) should have an instrument suitable for the job.
The Divex Mini O2 Analyser is that instrument. With past units one has had to hold the sensor over the pillar valve, being careful not to dilute with atmospheric air the oxygen content of the gas being read. What makes this one different is its positive connection to the cylinder.
Designed with divers in mind, it is shock and water-resistant and comes in a handy 7 x 10 x 3cm unit weighing 200gm. It is connected to a cylinder with a DIN fitting, the technical diver's favourite. If you use tanks in international A-clamp style you will need a converter, like those supplied with Poseidon regulators.
You calibrate to the oxygen level in air with the aid of a knob in less than 30 seconds and then run nitrox via this connection and flexible pipe through the unit. The connection kit has a simple flow restrictor to ensure that the sensor is not subjected to damaging over-pressurisation.
Response time is about 15 seconds and the oxygen content is displayed on a large LCD. The maker says the battery has a life of 4000 hours of usage and that the sensor lasts for three years. The analyser costs £210.
Mind my air!
Commercial vehicles carrying cylinders of compressed air must now display a green warning sign. It is probably a good idea to carry the same sign if you have one or more diving cylinders in your car.
Markat can supply either a magnetic patch (£5) or a sign that adheres by suction to the inside of your rear window (£3). I have tested the magnetic version extensively and it has stayed put through several car washes and never been removed by sharp-eyed vandals. When I don't need it, I fling it on to the inside of my (steel) garage door, where it sticks.
Of course, it is not suitable for cars that don't have bodies of ferrous metal, like Range Rovers or Espaces.
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