March 1997
Hue and I
John Bantin may be having trouble with fly-away hair, but what about the outfit? Is that mother psychedelic, or what? You don't have to be rainbow-coloured when you wear a Driduck membrane drysuit: they ran up this little number just
for our test
When Driduck suggested sending one of its membrane drysuits for testing, I was asked which colour I would prefer. Diving equipment can look rather sombre so to keep our pages looking as interesting as possible I asked them to make me one in any colour so long as it was bright.
Driduck took me literally and supplied a suit made as usual from seven component panels, but each in a different colour from its range. The effect was psychedelic - I looked like Joseph in his Technicolour Drysuit!
The Driduck name might not be familiar, but it has been making cold-cure membrane drysuits since 1990. These have been sold as "own label" brands but now you can buy a suit bearing the Driduck label.
The test suit appeared to be made from a strong tri-laminate material with seams glued and neatly reinforced with tape. The neck and wrist seals are made of latex material (heavier duty at the wrists) and these are nicely integrated with the main body of the material.
The cross-shoulder dryzip seems to be equally well bonded into the suit and leaves an opening of 86cm, so I had no problem getting in or out. The rubber boots looked very much like the standard product from a factory in Scotland, which are fitted to many different makes of suit.
The valves fitted to chest and shoulder are the Swedish-made Si Tech. The inflator has an easily managed collar to its hose, for disconnection, and the constant- volume automatic shoulder dump has a low profile to prevent it getting hooked up with BC straps. Both are mounted on strongly reinforced rubber patches.
The shins and knees are also reinforced with an additional panel of material. Pockets, one sealed by a Velcro flap, are positioned at each thigh.
Colour choices include black, silver, grey, yellow, orange, lime, pink, red, amethyst and royal blue. You can choose any single colour or combination - but you do not need to incorporate them all in the same suit!
The Driduck membrane drysuit costs from £320 to £450 with valves fitted, and including hood, gloves, 100g thinsulate and bag.
Driduck, 2a-2c Zigzag Road, Wallasey, Merseyside L45 7NZ. (tel. 0151-639 2714).
Fill, dump, save a life
Divers tend to divide into two groups nowadays. The "technical" divers want to carry as much redundant equipment as possible, in case of technical failure. The rest want to simplify their rigs and take the minimum amount of gear underwater with them.
The Buddy Auto Air appeals mainly to the second category. Instead of carrying an alternative second-stage regulator and hose, the diver with the Auto Air uses the hose from the direct-feed control to the BC.
The Auto Air is a multi-function item. It allows you to fill or dump air from your BC and breathe from it as an alternative second stage, should you need to give your primary second stage to an out-of-air buddy.
There is nothing new in that. The Auto Air and similar items, namely the Apeks Octoplus and Scubapro Air 2, have been available for a long time. What makes AP Valves' Auto Air slightly different is that, should the user's cylinder be empty, it will draw air instead from inside the BC. This gives a couple of extra breaths or, if a 400ml auxiliary cylinder is fitted, more than a few. In certain circumstances, that could make a difference.
AP Valves has gone to great pains to get a top-flight breathing performance from this valve, so what is the downside of using this instead of the more normal alternative second stage?
It is mainly one of comfort. Breathing from a valve restricted by the length of the corrugated BC hose to which it is attached could not be called pleasurable, but assuming you would use it only during an emergency (including an ascent), one could put this element of discomfort to one side.
I have tried out the Auto Air extensively in practice situations and found it usable. The breathing resistance seems first-rate.
Unfortunately, however, BCs rarely get the care and attention given to regulators after a dive. They are seldom rinsed in fresh water, and because the Auto Air is attached to the BC it will be inclined to suffer the same fate.
One often hears the tell-tale hiss of such devices free-flowing slightly because they are no longer in pristine condition. This is undesirable, even though the amount of air lost is probably more irritating than dangerous.
Sometimes this free-flow effect is due to an Auto Air being out of balance with the intermediate pressure provided by a particular regulator's first stage. In fact the Auto Air needs to be tuned by adjusting the tension on a spring, using a wrench applied to a small nut inside its end cap.
You must do this on installation. I discovered this fact hidden among the small print of what I consider to be an over-complicated instruction manual for a very simple bit of kit.
I have suggested to AP Valves that this important point be made clearly on page one. It would save a lot of people being disappointed by an otherwise worthy product.
The Buddy Auto Air will fit most BCs and costs £94.39 (or £47 extra when supplied instead of a normal inflator on a Buddy jacket).
AP Valves, Water-ma-Trout Industrial Estate, Helston, Cornwall TR13 0LW (tel. 01326 561040).
The cheaper alternative
Some time ago I reviewed two regulators from the same manufacturer. One had a "balanced" piston first stage, one was "unbalanced". The manufacturer later took me to task for "obviously not understanding the philosophy behind the unbalanced design".
I was told that because the breathing resistance increased once the tank reached reduced pressures, it formed an added safety point in that it reminded the diver to check his gauge. My reply was of one word, starting with the same letter as my surname!
The whole and only point of an unbalanced piston first-stage design is that it is cheaper than the balanced alternative, making it a sensible purchase for diving schools and those likely to be using regulators in shallow, undemanding water.
This economy is paid for in lost performance, especially towards the end of the dive if the cylinder pressure falls below 50 bar.
Mares has sent me its new unbalanced piston first-stage design to try. It is called the R2 Nikos, or Nikos Escort when fitted with yellow as opposed to black coded front and yellow 100cm medium-pressure hose.
The first stage has one high- pressure port and four mp ports. The air is routed within it to provide classic Mares Dynamic Flow Control (DFC). This is combined with a wide-bore hose to make the flow of air, and hence breathing effort, as easy as possible within the design constraints of a low cost regulator valve.
The second stage is a simple, robust-looking plastic design. It has a little vane inside it that diffuses the air flow and gives a pleasant effect in the mouth.
If you want a simple and inexpensive regulator, the Mares R2 Nikos or R2 Nikos Escort could be it. The price is £140 for either.
Blandford Sub-Aqua, Holly Industrial Park, Imperial Way, Watford, Herts, WD2 4TP (tel. 01923 801572).
Night light
Have you noticed that the chart tables in wheelhouses of boats are lit with a red light at night? This is because a red light does not destroy the night vision of the helmsman.
The On Board emergency light gives a similarly red light that allows a diver to keep his night vision and still be able to read the LCD screen of his computer. It clips securely on with a reusable cable tie and gets its light from an LED.
It is a novel idea. It is barely bigger than the AA battery it runs on and is triggered once submerged in water. I clipped it to my BC and found it acted as a useful marker for my buddy during a night dive.
Once I had turned my light off and waited until my eyes adjusted to the darkness, I was able to use it to make a computer-safe ascent if necessary. Unfortunately, lamps never fail at a convenient moment and should a diver be plunged into unexpected darkness, I cannot see him waiting coolly until he has full night vision.
So always carry a spare working torch in the pocket of your BC, but by all means use this little gem of an idea as an indication to other divers of your whereabouts, should you choose to operate with your light switched off.
I am told it should last for about 100 dives. Is that about 100 hours? The On Board costs £30 plus £5 p&p.
On Board, Unit 1, Darwen Enterprise Centre, Railway Road, Darwen, Lancs. BB3 3EH (tel. 01254 771497).
Time and tide, roughly
Coxswains who have left the club RIB tied to the quay at Salcombe during a high spring tide, and have come back after a long lunch to find a very dry boat dangling precariously from its cleats, will benefit from this product.
Computide is a tide prediction package with software suitable for IBM-compatible PCs equipped with Windows. It gives accurate tidal forecasts either for the UK, or for UK and European ports, depending on which version you buy.
Although obviously aimed at those yacht owners and ship operators whose wheelhouses are equipped with state-of-the-art electronics, including onboard PCs, I am told that the maker's previous tide computation software has proved popular with divers.
Loaded on to a PC 486 type with 4 megabytes of RAM (although it will run on a 386), the installed program occupies less than 1Mb of disk space.
Yours truly, a fully qualified computer buffoon, found no trouble getting it to work by simply following the instructions.
Choosing one of £370 UK (or 700 European) home ports, a date and a time, one is immediately presented with the appropriate tidal curve, together with a line representing the draught of your vessel. The figure for draught may be preset to suit. It is easy to spot the times of high and low water, and the tidal height is visually obvious.
There is also an axis line (movable by cursor) to represent the time of day.This information is also presented in figures on screen.
Computide is extremely quick and easy to use, and boat-owners entering any of the listed harbours will be gratified to know exactly how much water they might have under their keel. It also makes a good computer game for divers.
Its value for those who wish to use it to decide when to dive may be less than the makers wish us to believe, however, because the program uses the Admiralty method NP159 to make its calculations.
This "simplified harmonic method" of tidal prediction is accurate only to within 20 minutes. Anyone who has needed to know when that vital window of slack water over the Kyarra off Swanage occurs will be aware that this method is not sufficiently accurate. The Admiralty uses up to 120 tide angles and other factors in its published tidal calculations, whereas this method uses four.
The other point is that the program refers to ports, and experienced divers know that slack water at a dive site can occur at a very different time from that in the nearest harbour.
Still, for any club divers who simply cannot grasp the use of GMT, calendar, chart, tidal diamond and tide table, this computer software could be used as a teaching tool.
Computide costs £39.95 for UK ports or £49.95 for UK and European ports.
Softwave, Aranmor House, Kingston Hill, Kingston, Surrey KT2 7LY (tel. 0181 942 3334).
www.softwave.co.uk
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