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Chris · 05-30-2002, 07:02 AM,

"Just a background, I like to keep a 1.4 ata partial pressure (p.p.) profile. I don't usually enjoy pushing the envelope into the 1.5 ata or 1.6 ata, though I've been there and my Uwatecs worked like a charm. Concerning algorithms: The opinion that the Suunto and Uwatec computers are more conservative is false. If the computer's O2 ata p.p is programmable, then the maximum depth and bottom time algorithm is adjusted. Most computers come set at 1.4 (which most dive tables are set for), then they can recalibrate for your current location in the water throughout the dive. Others come with 1.5 ata. Which is halfway between the 1.6 emergency contingency models. (In most cases, most educated divers try to keep their p.p. at 1.4 no matter what their depth or dive profile. Even in extreme technical diving). My hose-less Uwatec for example can be set from a Maximum Operating Depth (MOD) from 1.2 ata to 1.95 ata. (John Hardy, who has since passed away, was the leading editor for scuba diving's scuba lab, which tests a variety of brands of dive gear. He said that they initially made a mistake in publishing that some computers were more conservative than others, but because of content space they couldn't fit everything in they wanted -which happens quite often) When I spoke with Mr. Hardy, he also mentioned an upcoming side-bar editorial that was being published afterward. It came out explaining that most of the dive computer manufacturers had not been making any advances to their algorithms, though medical research and advancements had forecasted some of them could be changed. Many were based solely upon the Navy tables (that's about 50 yrs old now) and Haldane's gas theory research, without adaptations to any current research. This publishing angered many advertisers as they were promoting "latest and greatest" computer advances with only a name change and new packaging. (This is still occurring, you can see the same computer under many different brand names with maybe just a slight change of read-out, etc) I started looking into the Uwatec line of computer long ago because Uwatec was considered by many to be the brains behind the scene when they were partnered with Drager Rebreathers. I bought into the Uwatec computer line long ago because it had the most reliable and proven track record in the tech-diving community. Everyone was using the Aladin Pro at that time because it offered all the liberal profile you wanted along with the most accuracy for the depths you wanted to go. They also offered an adaptable algorithm, which was accounting for and adapting to the ACTUAL diver behavior, temperature of the water, as well as the workload. That's important to me here in Minnesota especially for temperature changes and the environment your in, the effect of your workload and movement, and a combination of these things. This was by far and huge advance in the development of a profile, based upon newer research on Doppler examination of bubble formation. (Remember that PADI RDP Wheel that was designed, it offers multi-level dive profiling, which none of the tables were designed to do. The tables were designed of the Navy's basis of having divers descend for a specific task and ascend. That's not the recreational diver, we dive multi-level profiles on almost every dive.) Later I started using some of the Oceanic computers, but my DataMax went on the fritz, and then the company started recalling them. (All Aeris have been recently recalled as well, SAME manufacturer). I got rid of it and kept with my Uwatec. I've only dove the Suunto computers once and for my dive profile, it was not a computer I wished to have. I like long, deep dives, especially on vacation. There were two others with the Mosquito, same result, but even more conservative profiles than I. The Suunto's were locking out on a regular basis, though the Uwatec Aladin Pro and hose-less Air Z-Nitrox computers were all showing accurate profiles and matched with the freedom I wanted for my own diving, yet still trying to avoid decompression diving. Recently, there is a breakthrough with the Uwatec Smart Pro (and all the Smart series). They still utilize the adaptable micro-bubble level. But more importantly for the smart series is the level stops it can recommend for micro bubble build-up. I recently read the debate of Haldane's off-gas theory versus Hill's, from Alert Diver (DAN research). Haldane said that by stopping half-way to the surface from your depth, you decrease the 1/2 life p.p of the gas, improving deco and safety. Hill suggested that a divers profile could go straight up to the safety stop. (Both following a slow ascent rate) After a long debate and a lot of research, Haldane was proven the superior method. Hill theory could potentially increase your chance of type II DCS (neurological sickness - very common), more so than Haldane's theory. And the Smart series of computers now advice you of the micro-bubble level stops, without limiting your dive freedom or profile. I hope that some of the other manufacturers and distributors continue to improve upon their dive computers and their potentials as I'm always looking for my next safe, fun and reliable toy."