Robert, I'm surprised you are not simply breath-hold diving, you old Luddite! The heart-rate monitor is not there to tell you you are having a heart attack. It's there to take your heart-rate/body function into consideration when calculating your deco - or did Dr Buhlmann base his model on your supreme example of human fitness?
John, I had no idea that there was a new decompression algorithm out that could "take heart-rate/body function into consideration when calculating your deco". I didn't even know someone had come up with a theoretical formula (or any data) that could meaningfully relate changes in heart-rate to increased DCI risk. Or is the Galileo's heart-rate function something like the Uwatec SmartPro's "micro-bubble level warning feature" - "best guestimates" based on the very best science that some guy in the marketing department found on the internet?
Neither compasses nor SPGs are life support equipment as you do not die if they fail. Your air supply is your life support equipment. I don't need fully redundant computers to make good decisions on a 30' max dive.
Sure, nobody needs redundant computers on a single 30 meter dive, but if you don't have redundant time and depth information then aborting the dive is probably the right course. More important, if you are on a dive trip, only carry one computer, and it fails, then it's back to tables and you'll need to clear for 24 hours or more before you resume diving. Same deal even if you have a spare computer that lives in your cabin.
It's not about streamlining, it's about not having your SPG drag over the bottom if you want to make a shot close to the substrate. When you only have your SPG as a backup for your AI computer then I guess you can stow it out of the way.
Notwithstanding that Scorpiofish was talking about integrated octo-inflators (and I agree with him), not SPGs, there is absolutely no reason for the SPG to drag on the bottom. As Drew knows very well, I don't claim to be DIR at all (and I also agree with Craig that "a DIR photographer" (like a photographer dive buddy) "is an oxymoron"). Anyway, I usually keep my analog SPG clipped to the left chest D-ring, not the one on my left hip where George insists it should go. I can read it at a glance, no hands, just as easily as the people who with transmitters on the 1st stages.
I do use happily wear my my spare 2nd on a necklace instead of a scum-ball. And in fairness to "real" DIR divers (whoever they are), I've never seen even a wannabe neo-DIR diver drag their SPG over the bottom. Nor a necklaced spare 2nd. It always amazes me how many ostensibly experienced PADI-trained divers think its ok to swim over reefs dragging a huge console (depth gauge, SPG, computer, compass) and a nice bright yellow "Octopus" over the corals. They also seem to get very offended if you mention it to them, even if you do it very nicely.
Of course, choice of computer also includes choice of decompression models, which is another whole subject in itself. RGBM with deep stop vs Buhlman with heart rate vs Haldane with tables. I think you best should also consider the computer model as part of your decision making. A computer is for showing deco limits and those vary between different deco models. PS: George, let's not give Craig ideas on that vibrating SPG and where to store it.
I agree with Drew 100% on this. Only a few weeks ago I heard a diver disparaging his new Suunto RGBM computer "because it doesn't give me as much bottom-time as the Uwatec Aladdin did, especially on a trip doing several dives a day." I had blithely assumed the reason people become Suunto owners is that they wanted their computer to use a better algorithm which takes into consideration repetitive multiple-day diving, reverse profiles, etc. I just wish Suunto would release a RGBM computer with a cleaner configuration - multiple gas mixes yes, but no wireless, no compass, no email, etc. With a big, easily readable display, and at a price that makes it possi ble for me to buy two of them without taking out a bank loan.
The other factor that needs to to be taken into consideration, of course, is reliability. I know that it's not a question of whether a dive computer will fail, but when. That said, I haven't very good luck with Suunto computers in the past.
If Suunto really does come up with a computer with a vibrating anal probe, I'll think I'd like to sign up to be their agent. It opens possible vistas of whole new markets for "recreational deep diving."
Edited by frogfish, 07 May 2007 - 06:31 PM.