COMPUTER Oceanic Atom
Living in one place, its sometimes hard to get a perspective on what its like to live in another. Procedures you take for granted when diving may be very rare elsewhere.
     Take helium, for example. Its 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, Ive 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 companys 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, its 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 youre 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 its 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 à there are just so many aspects to the Atoms 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 computers 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 Atoms 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.
     Its 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. Theres 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.

Used as a punishment
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, Im 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 couldnt 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. Thats 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. Its also available without transmitter (£399), and additional transmitters cost £224.
  • Oceanic SW 01404 891819, www.oceanicuk.com

  • Divernet Divernet
    + 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