The story so far. In 1994, during a visit to the Mares factory in Italy, I was shown the prototype of the company's latest semi-dry dive suit, the Isotherm. Not being one to miss an opportunity, I was measured up for one. In 1995, the Isotherm suit arrived, and I reviewed it for Diver.
I was seduced by its fit, and the reaction from others when I wore it. It was so flattering even my wife fancied me in it! I've since used it extensively in the Mediterranean and for very long dives (90 mins) in the northern Red Sea.
With its 6.5mm fabric made from a sandwich of metal plush, neoprene, Thermotitan and jersey, it offers the highest level of insulation in a semi-dry suit. The metal plush, in combination with the neoprene, minimises heat loss, and the Thermotitan material causes heat passed from one's body during pre-dive surface time to be stored and released during the dive. The O-ring-in-latex-style seals at the neck, wrist, and ankle (concealed under neat Velcro cuffs) keep the flushing of cold water to a minimum. My only reservation was that the drysuit-style zip across the shoulder felt a little restricting when not under water. It also accounts for a large part of the cost.
Now 1996 is with us, Mrs B has an Isotherm suit of her own. It's of a less dense fabric (5mm) and comes with a less restricting wetsuit-style zip, though this is still positioned across the shoulders.
More to the point, her suit came off-the-peg and it fits her remarkably well, even though she's not an off-the-peg shape. Her suit may not be as thick as mine, but then she's got an extra layer of (charming) epidermal fat to make up the difference. The Italians have always had a flair for styling and these semi-dry suits are no exception. They don't hold back when it comes to accommodating the female shape either.
Unfortunately, the seals on the ladies' suit supplied were much too large for my wife's slim ankles. They were probably more suitable for a man. They tended to bunch up under the covering velcro flap. This greatly reduced the efficiency of the suit. The wrist seals were perfect. I hope Mares will address the problem.
All Isotherm suits come with a separate matching hood.
Was it an unnecessary gadget? Not if you had your hands full, as you might with a camera for example, or if you were instructing, or even learning!
Once the Divemate went into decompression-stop diving, its voice went silent and you had to unclip it and look at its large LCD. If the viz was not so good, it had a tap switch which turned on the display lighting. If you ascended too quickly, two large red lights flashed on.
So why, despite my enthusiasm, have so few been purchased in Britain? Because, made in Finland by Benemec, but marketed through Italy by Mares, means a purchase price of £460.
Benemec also makes the same computer in a simple wrist or console-mounted form, without the speaking voice. Now it has addressed the problem of high retail prices by selling both versions with the company's own name, or with the names of other national distributors. It's available with English, German, Italian and Japanese voices.
| The Mares whisper-in-your-ear dive computer proved too expensive for the average diver to buy. Now you can get the same thing, under different names, more reasonably. The Orca Pilot Audio will set you back £299, while the Benediver nitrox wrist-mounted model costs from £255. |  |
Thus, ORCA, a division of EIT in America, has introduced the English-speaking ORCA Pilot Audio. It's the very same Benemec computer as the Mares Divemate, and you can buy it here, imported by Sea & Sea, for £299!
For those who want a computer which can be adjusted to suit the O2 mix they are using, there is also a nitrox version for around 360. If you want the computer without the speaking voice feature (or display illumination), you can buy the ORCA Pilot in wrist or console mounting for only £219 (or £259 in nitrox form).
Hydrotech also imports the non-speaking versions. It calls them the Hydrotech Data (218) and the Hydrotech Data Nitrox (£255).
All these computers are powered by a user-changeable battery which will last for about two years of average diving in the audio version, longer without the voice mode. There is a special programme for kick-starting a tired battery back into life, so that you can get the most use out of it.
User-adjustable displays include metric or imperial measurements; and the user can choose if he prefers to see the water temperature or the maximum depth achieved.
Divers can also choose between a normal or hard diving scenario for the modified Buhlmann algorithm.This uses an eight-tissue group model with half times ranging from 5 to 480 minutes. Altitude selection is user selectable in five steps from sea-level to 3500m.
Under water, besides displaying things like remaining no-stop time, depth, water temperature or maximum depth achieved, it will, once into deco-stop diving, display stop depths and total ascent time. The ascent rate can be adjusted from 20m/min to10m/min.
Surface mode displays dive time, maximum depth, surface interval, dive conditions chosen, and 'do not fly' indicator. It will scroll no-stop times and depths, and indicate the tissue group which will become saturated first at that depth. Memory mode stores the last ten dives or the last ten hours of diving. Planning mode is used to simulate repetitive, multi-level, decompression stop dives, and dives at altitude.
In addition, nitrox versions are user-adjustable for O2 in one per cent increments from 21 to 50. PpO2 exposure limits are adjustable from 1.2 to 1.8 bar, allowing the diver to set his own safety limit. This has to be done before the start of each dive, and the computer demands that it is done, so there's no forgetting! The computer program limits the depth to the maximum ppO2 level chosen.
During the dive, the computer displays current ppO2 and the CNS level in percentages. After the dive, oxygen toxicity units (OTUs) calculated are displayed as a total body oxygen dose.
There's a Windows-based PC interface and program available which works with all versions of the computer. It is called the (Hydrotech) Data Reader.
These computers, whether in talking form, or in nitrox form, or in both, represent good value, and I'm sure we'll start to see them in common use.
The Verti-Clip from A.P.Valves comes in two parts. It is a simple device which, when sandwiched either side of the webbing on which it is mounted, will cause a D-ring to stand erect, making karabiners easy to hook on. It's like having another hand! Additional D-rings can also be added using the Verti-Clip to maintain them in position - a little experimentation is necessary to find the most useful position. The Verti-Clip can also simply be used as a fastening - but only for D-rings which are likely to be subjected to the lightest of loadings.
You've probably heard of Z-Drive for powerboats. Well, these are V-Drive for divers! These latest fins from the American Oceanic company (left) are made in Italy - the place where most good fins seem to come from.
First impressions are of a large, shovel-style thermoplastic blade, with a V-shaped cross-section supported by a strong central spine on the underside. There are four longitudinal struts of soft rubber-like material on the upper surface. A capacious foot pocket extends virtually to the heel, and the design is finished off with a substantial heel strap with quick-release buckles.
In the water, I found the Oceanic V-Drive fins certainly got to grips with the water, and I found their performance to be indistinguishable from the Italian-made brand leader that I usually use.
Interchangeable with the standard Apeks valve (which is fitted as standard to almost every drysuit on the market), it does the same job but is simply designed to stick out less prominently! It costs £22.48.
or
