 |
|
COMPUTER
Living in one place, it's sometimes hard to get a perspective on what it's like to live in another. Procedures you take for granted when diving may be very rare elsewhere.
Take helium, for example. It's expensive, but not that difficult to come by in the UK.
I heard a diver query why people should want a three-mix nitrox computer, one that can be programmed for the use of three different mixes during a dive.
"Surely people would be using trimix, and switch to a rich nitrox mix only for accelerated deco at the surface," she said.
Well, I've got news for her. In many parts of the world, the only breathing gases are those derived from nitrogen and oxygen. So a diver might use air as a bottom gas, nitrox 32 as a travel gas and nitrox 80 as a deco gas.
Another point; when Sergio Angelini, head of the Swiss diving computer company Uwatec, was questioned about the absence of a trimix version in the company's latest range of computers at their UK launch last year, he said: "Tri-mix tables are voodoo. Uwatec does not yet have a properly researched trimix deco table available. Until it does, it's concentrating on the use of nitrox."
Now, having upset all the technical diving training agencies, and those British manufacturers that make trimix computers, let me tell you about the Oceanic Atom, a three-nitrox-mix decompression computer recently arrived from the USA.
Oceanic appears to feel the same as all the other major computer-makers about trimix. The Oceanic Atom is its top-of-the-range three-mix nitrox computer, in wristwatch format. Like some others, it is wireless gas-integrated by means of a radio transmitter that fits to the high-pressure port of the regulator first stage.
However, Oceanic goes a couple of steps further. In common with the latest products from its European rivals, it offers the facility to integrate the computer with all three supplies of the gases being breathed.
I tried a standard Atom with one (dark grey) transmitter for the primary supply, but both yellow and green transmitters (for high levels of O2) are available as optional extras. PC download software and a USB interface cable come as standard. The same interface system can be used to upload settings that can change the main time and date, set alarms and adjust various utilities such as changing the sampling rate and transmitter link codes. These last can also be set using the buttons on the diving computer.
The Oceanic Atom is a full-function decompression computer. However, in surface mode it works as a typical digital calendar/watch/chronograph, with a dual-time function for keeping tabs on things at home when you're in a different time zone. It has four buttons for setting it up.
You can set it for any nitrox mixes between 21 and 100%, and you can vary the ppO2 alarm setting from 1.2 to 1.6 bar. You can set alarms in advance for maximum depth and a range of minimum tank pressures. The remaining dive-time alarm is based on worst-case tank pressure, various degrees of tissue-loading in no-stop scenarios, turn-round tank-pressure (when it's time to head back), and even elapsed dive-time.
The utilities setting sequence allows you to enter a fixed conservative factor (I did) and to pre-set from three choices of safety-stop depth and time (three or five minutes or "off").
As usual, it took me a while to get my head round how to do this. The instruction manual is an exhausting read, with no short-cuts. You have to digest its 150 pages from front to back. It desperately needs short summaries at the end of each section Ð there are just so many aspects to the Atom's menus, sub-menus and functions. Info overload!
I am sure that those of you in full-time education will have no problems. As Groucho Marx said: "A seven-year-old boy can understand this, so get me a seven-year-old boy!"
Funnily enough, operating the computer's buttons also proved difficult, because they are hidden below a flexible scratch-guard and not quite where I expected to find them.
I was also surprised to find that I needed to use the extension strap even with a wetsuit. I normally need one only with a drysuit. I suspect that those with more manly wrists might find the Atom's standard strap too short even to use as a daytime watch, which is a shame, because it is quite an attractive proposition as digital watches go.
The Atom also allows you the option to turn off the wet-start function, which makes it go into diving mode once you are deeper than a couple of metres. Why that option? Do some divers really want to spend all that money on a computer, only to use it as a watch under water?
I think it has more to do with the fact that for many years all Oceanic computers had to be turned on manually before diving, and I, like many others, often forgot to do it.
It's almost as if Oceanic is in denial that this was a bad idea so is giving you the option to do this with its latest all-singing, all-dancing product.
Under water, the Atom shows all the information you would expect, including a bar graph for no-stop deco nitrogen-loading/oxygen-loading. There's current depth and maximum depth, dive duration, no-stop time remaining and gas-time remaining, based on previous usage and depth.
I was rather surprised when it came up with the legend "TOO LONG DIVE". Had I passed a pre-set dive time, or was it telling me that I had missed my lunch?
I had trouble getting a tank reading before getting wet and initially concluded that the transmitter was not working. It was only when I became very low on air during that first dive and the computer displayed "LOW AIR TIME" along with "VIEW AIR", that I concluded that I needed to press a button to get that all-important tank-pressure and remaining air-time information.
Press the appropriate button briefly and there it is. Press it for a bit longer and you get the watch function. Effectively there are three displays available under water.
I have been critical of Oceanic computers in the past. I have no way of knowing if the information they disseminated was "correct"; I could only compare it with that on other computers I used alongside them. I felt that they were either too cavalier with their no-stop times or, once into deco-stop mode, over-cautious. It was almost as if deco stops were being used as a punishment rather than as a technique.
So I set up the Atom with the optional caution-factor and found on my first dive that, as far as no-stop times were concerned, they were very much in line with those displayed by the Uwatec and Suunto products sitting on my same wrist.
What an agreeable surprise, and what a good omen for the sales of this product to European divers, too. But my elation was short-lived, I'm afraid. When I did a second dive, I found that the familiar less-than-cautious Oceanic algorithm came into play, giving me masses of no-stop time when the Euro computers alongside it had me well into several minutes of mandatory deco stops. For example, with a dive as part of a series, the Atom is significantly less cautious than a similar Suunto, with its RGBM100 algorithm.
With the Atom you can program in a safety stop, and this counts down in both minutes and seconds. Along with all the other messages on the display, the word "STOP" appears.
It certainly gives you a lot of information. In fact it has the ability to give you so many different messages that I couldn't list them all here. It would have been nice to find a summary somewhere in the manual.
The battery is user-changeable and you can download all the information to your PC using the cable and software provided. I believe a lot of people will own an Atom without ever discovering the limit of its capabilities.
That said, my impression after using the Atom extensively is that this is a computer that has masses of features, but the one it really needs is an algorithm suitable for repeat deco diving. That's probably something most purchasers on the other side of the Atlantic will never miss.
I began to understand the reasoning behind the design of the Atom on a recent visit to the Cayman Islands. Many US holiday divers complained bitterly when they were made to wait a full half-hour between dives!
These people will find a computer that has loads of features yet does not impinge on their diving time to be a very attractive proposition.
The Oceanic Atom with one transmitter, PC interface (USB) and software costs £675. It's also available without transmitter (£399), and additional transmitters cost £224.
Oceanic SW 01404 891819, www.oceanicuk.com
 |
+ Attractive-looking package
+ More in line with European deco predictions for a single dive when "caution factor" is selected
|
|
 |
- Hard-to-follow manual
- Air information on alternative display
|
|
|
|
|
|
ALTERNATIVE AIR SOURCE
"Egress" is a word used by estate agents. They use it when they mean a door but it sounds more grand and therefore more expensive than a word we all understand. It actually means "exit", and I suppose it could be used as an alternative to "escape".
Those divers who unexpectedly find themselves under water without an air supply would be very glad of an exit or an escape. That's where the new Apeks Egress comes in.
It's an anyway-up regulator balanced second stage that can be used as an octopus rig or as a stand-alone regulator fitted to a suitable first stage and a stage-cylinder. Its great advantage is that you can stuff it into your mouth any way up and still breathe from it. As such, it accommodates panicking out-of-air divers, tekkies, left-hookers and anyone else you might run into under water.
I took an Egress off for some extensive use at 50m-plus and found that, although it didn't breathe quite as easily as my primary second stage, it was still pretty good. I used it as an octopus-rig and went in with it both on a necklace and also stuffed into the pocket of my BC.
"Oh, that's going to free-flow," prophesied one of my dive buddies when he saw me put it into my pocket, but did it?
No! It wasn't in that triangle-of-visibility so beloved of PADI diving instructors, but neither was it trailing among the coral wreaking ecological havoc and filling itself with sand and grit ready for the unsuspecting user.
I've seen divers practising out-of-air ascents and getting into all sorts of tangles. It usually stems from rigging a right-handed regulator on a hose on the donating diver's right side.
Good for him, but of little use to anyone who may need it in a hurry. Instead of getting into all sorts of hysterical arguments about where you stow your octopus-rig, why not get an Apeks Egress and exit the discussion? That's what I recommend.
If you are switching to a gas supply from a sling-tank, a regulator of this type makes hesitation unnecessary before you stuff it in and heave. Of course, it's unlikely that you will be using a deco gas at much depth but oxygen is pretty dense, unlike trimix, so it's nice to know that you have a regulator that breathes without much effort.
If you're planning to use it, you simply clear it with an exhalation. If things have become a bit dire and you've got nothing to blow, you'll need to use the purge. That's the yellow side, but it doesn't really matter. You grab it between thumb and fingers and press, and the yellow side flexes to purge. It's pretty foolproof.
So what was my overall impression of the Apeks Egress as an octopus rig? As they used to say in the '60s, the Egress is way out, man!
The Apeks Egress as an octopus complete with hose costs £103.
Apeks Marine Equipment 01254 692200, www.apeks.co.uk
|
+ Any way up or down octopus
|
|
|
|
|
|
REGULATORS
The French invented scuba-diving as we know it. Yes, you may not like it but it's true. It was Benoit Rouquayrol and Auguste Denayrouze who first came up with the idea of scuba-diving, but it was in occupied France during the war that Emile Gagnan and Jacques Cousteau got the idea off the ground.
We were spared an underwater invasion by Nazi divers only because they couldn't find any tanks big enough (and those Tiger tanks were pretty big!).
That was then and this is now. Today Beuchat continues to hold the tricolore for French-made scuba-diving equipment.
The Beuchat VX200 is a top-range regulator with a diaphragm-type first stage that comes equipped with four medium-pressure and two high-pressure ports. The rather large black plastic second stage has a dive/pre-dive venturi control and a breathing-resistance adjustment knob.
Large parts of this second stage are made of metal, and it has a finned metal heat-exchanger in-line where the mp hose connects, so that it looks perfectly suited for use in cold fresh water. It's a great pity we weren't sent one for our recent coldwater regulator test.
French divers still tend to sport Clemenceau moustaches, smoke untipped Gitanes and like to refresh themselves with a tot of pastis after a dive. They haven't just started wearing black because of tech-diving fashion because they never stopped wearing black from the days when that was all you could get.
Typically, the VX200 seems to represent some good old-fashioned values too. I used it alongside another top-performing regulator, an Italian Mares Abyss, and felt that it gave air in equal measure. Of course, there were some slight differences, but nothing of any significance.
I especially relished the large conventional mouthpiece and the old-style exhaust T that routed exhaled bubbles away from my line of sight. The purge button was exactly that, a button. You couldn't mistake it, and the purge is just what you want Ð not too strong but otherwise very effective.
It is one of those bits of kit that you use and forget about. No one at a dive site is going to bother asking you about its technical spec, or even how much it cost. It's just not that glamorous. It may even be regarded as boring by some, but it does the job and it costs £329.
.
Typhoon International, 01642 486104, www.typhoon-int.co.uk
|
|
|
|
FINS
Some people think that the most important thing to come out of Genoa was Christopher Columbus's idea of finding the New World, but that's not all.
When it comes to injection moulding of thermoplastics, nobody can beat the Genoese. Cressi-sub was one of the first in the business after World War Two and the company continues to be at the forefront of the industry.
What does the company make in this way? Fins and masks of course!
That's not to say that Cressi always gets it right. It produced one beautiful style of fin, the Space Frog, that I rated highly when I tried it. But some divers clumsily climbing ladders to reboard rolling dive-boats found that they could trip and snap these earlier fins in two. So it was back to the drawing board for the Italian fin-makers.
The Cressi Rondine name is an old one. Rondine Garas are those long fins beloved of competitive freedivers and certain scuba divers who always dive alone. Well, they end up diving alone after they've kicked their buddies in the face a couple of times.
These massive Rondine Garas should not be confused with the latest Cressi Rondine A fins, which are intended for use by scuba divers.
Also, do not confuse these fins with those floppy, soft rubber split-fin products beloved of obese American divers because they can flap their legs as much as they want without getting cramp. These fins have the fairly rigid plastic paddle that characterises so many Cressi fin designs.
In effect, these fins are for people equipped with muscles in their legs. Like so many other things in life, you need to be fit to enjoy them.
A soft edge and foot-pocket are provided by combining this harder plastic with a soft rubber compound. Rigidity at the edges is obtained through use of a material that's harder still.
The massively long foot-pockets easily swallowed all of my size 12s, with a bit of overhang left at the heels. This meant that there was no energy lost at the ankles, and I could get all of my thigh and calf effort out into the water.
When I found myself needing to swim out from a shore in Grand Cayman to reach a distant reef wall, there was no problem.
The hotel's little dinghy had been lost to Hurricane Ivan, and the dive centre offered the hire of small diver propulsion vehicles to ease the pain of the 500m swim, but I needed to take my camera, so had no hands free for the DPV.
I resorted to paddling out on my back with my BC partially inflated, and finning as efficiently as I could. I was surprised that my young buddy had trouble keeping up with me, equipped as I was with the Cressi Rondine As - even though he was being towed in electronic luxury! So I can confirm that the Cressi Rondines do work.
When it came to taking the fins off, I encountered a slight problem in that with the straps pulled tight it was impossibleto stretch them over that extended lip at the heels.
I needed to develop the technique of loosening the straps at the adjustment buckle before I reached boat or shore. Better buckles would see this issue resolved.
That said, if you have the legs for them, these fins could be the perfect ones for you.
Cressi Rondine A fins are available in four colours and sizes XS-S, S-M, M-L, L-XL. They represent reasonable value at £69 per pair.
Cressi-sub UK, 01484 711113, www.cressi-sub.net
|
+ Very effective if you have the legs for them
+ Good value
|
|
|
- If you get cramp - get fit!
- Buckles could be improved
|
|
|
|
 br>
|
|
GLOVES
Choosing the right gloves for diving when the water is cold can be a problem. Dry gloves afford me all the dexterity of a boxer who wants to scratch an itchy eye, but they can keep my hands relatively warm.
The wet glove alternative is fine for a time but eventually I lose any dexterity I might have had. That is, once my fingers have gone completely numb.
Pinnacle, the maker of the Pinnacle Polar woolly lined wetsuit I still often use when conditions are right, now also makes matching neoprene boots and gloves. Naturally, the boots are suitable only when a wetsuit is appropriate, but I had high expectations of the 5mm neoprene gloves with their Merino wool lining.
They were certainly warm enough to wear when dry and getting prepared to dive in air temperatures that hovered around the freezing point of water - and the freezing point of any part of my body, for that matter.
So, chucking my dry gloves lightly to one side, I substituted the Pinnacle gloves for a dive in 3°C water that looked anything but inviting.
Aaahh! After only 20 minutes my hands really started to hurt. It was my mistake, and the wool lining could not save me from that. However, in warmer conditions such as you might find in the sea around Britain in the summer, I am sure they would prove ideal. They are beautifully stitched and glued, and have reinforced palms and fingertips.
They also have a Velcro-equipped wrist strap that allows you to tighten them over your suit wrist seal, and effectively reduce the amount of cold water flushing into the gloves.
Pinnacle Karbonoflex gloves with Merino wool lining are available in a full range of sizes and cost £35 per pair.
AirSub International 01404 890196
|
- If it's cold enough, use dry gloves instead!
|
|
|
|
 br>
|
|
|
