COMPUTER Dive Rite NiTek
Dumbing-down was a concept invented in America. Thats not surprising. Its whats needed when you have a vast population drawn from disparate cultures and speaking different languages, homogenised into one incredibly prosperous industrialised society.
     Simply constructed cars, fast food and pared-down education have each been spawned from such a philosophy, and no-one can deny that General Motors, McDonalds and PADI have each been very successful in their own fields.
     But not all Americans drive gas-guzzlers and eat only bap-bound burgers, just as not every American diver sticks to no-stop dives at less than 20m.
     With such a huge population, the USA must have more divers who like to go deeper into their chosen activity than Britains entire diving population.
     The term technical diving was also coined in America, mainly to distinguish those who dive like Europeans from the majority who certainly do not. Dive Rite, headed by Lamar Hires, a technical trail-blazer, has aimed to supply the demand for diving equipment that goes beyond the Recreational Dive Planner and the lurid Lycra suit.
     It came as no surprise to find Dive Rite supplying proper decompression computers back when most US divers thought that using a diving computer meant concentrating on keeping its display-graphic from entering the red sector.
     The most high-profile of these computers, this side of the Atlantic, has been the Nitek3. This was the first, and until recently the only, readily available computer that could keep track of a divers decompression status even if he changed to one of two alternative and richer mixes of nitrox for accelerated decompression during an ascent. But in all the excitement, the basic Nitek seems to have been overlooked.
     I meet many US divers who are both certified to use nitrox and happy to dive deep enough and long enough to require mandatory decompression stops. Many of them come equipped with this admirable bit of kit.
     With a display almost identical to the Nitek3 and a similar pair of push-buttons, the Nitek is considerably smaller and with a characteristically similar rectangular case with a stretchy nylon strap that should go round the fattest drysuit wrist.
     It can be adjusted for nitrox mixes between 21% and 50% and has a predetermined maximum ppO2 alarm set at 1.6 bar.
     There are no short-cuts with the manual. Far from dumbed-down, it is designed to be read from cover to cover. Dont hope to dip in midway and find out how to make the nitrox setting.
     First you must set the date and time, and whether you want imperial or metric readings. If it is not set for air, you must be sure to set your nitrox mix immediately before every dive.
     During the dive the computer gives the full range of information you need, including stop-depth, stop-time and total minimum safe ascent time once you have gone past the last of your remaining no-stop time.
     The build-up of absorbed nitrogen prior to that moment is represented by a bar graph of rectangles that gradually builds up, and in nitrox mode that is balanced by the oxygen-limit warning, with a similar bar graph of round blobs that build up on the other side of the screen.
     If at any time the figures in the display start pulsing, it means that you are doing something wrong. This is accompanied by both an explanatory icon and an audible alarm. You might be ascending too fast, or be too close to the ppO2 limit for the mix of nitrox youre using.
     If both the oxygen limit and the ppO2 limit sound early on in a dive, it probably means that you forgot to set your nitrox mix, and the Nitek has defaulted to a worst case theoretical 79% nitrogen, 99% oxygen setting. As this will happen at only 6m, you have time to get back to the surface and reset the mix adjustment. Alternate displays for ppO2, water temperature, and how long till lunch are accessed by pressing button A during the dive.
     It was a shame that the display had no independent illumination. This rather precludes it from use during night dives, or indeed dives around the coast of Britain where poor visibility might reduce you to peering at it with your torch.
     What proved most significant about the Nitek is that it appears to me to use the Buhlmann ZH-L16 algorithm, probably one of the most field-tested algorithms used in any diving computer today. Its siblings have always done well in Diver side-by-side comparisons and I had lots of confidence in the information displayed.
     It also seemed to want me to stop in the 5-3m zone for a few minutes extra after any deco-stop dive, although there is no displayed safety-stop as such.
The Dive Rite Nitek is PC-compatible and costs £296.
  • Sea & Sea 01803663012, www.sea-sea.com

  • Divernet
    + Performs well in side by side comparisons

    - No screen self-illumination
    - Laborious-to-read handbook when it comes to making settings