No deco and dive computers

[supergaijin]

Suunto's RGBM algorithms calculate differently from the 'Bend and Mend' Buhlmann models. A single dive decompression obligation is very different from a multi-dive one. Multi-day + multi-dive again calculates differently.

According to your normal dive pattern, YMMV. Change up the pattern and be prepared to see a different deco obligation.

 

[Willar]

My experience with my Suunto Cobra is that it will clear deco as you go up. I've run it to the edge of deco several times and rise at the deco counts down. Works great. Only time I had a long mandatory stop was when I blew the rate of rise coming out of a swim-thru... it gave me a 5 minute mandatory stop (and I did 7 minutes for safety).

 

[DevonDiver]

My experience with my Suunto Cobra is that it will clear deco as you go up. I've run it to the edge of deco several times and rise at the deco counts down. Works great.

I will reiterate from posts #76 and #79 - a computer will not necessarily clear deco on ascent. They can, and do, add deco (fast..) on ascent if the multi-dive / multi-day parameters push you beyond the faster compartments as controlling.

It is not wise to make predictive assumptions about decompression unless/until you have a sound knowledge of the algorithm and principles that your particular computer is using for deco calculation.

I've seen more than a few divers get themselves into situations beyond their training/preparation because of this very assumption.

 

[cbm32]

I have heard many times that the world was going to end on a certain date too. So far, things keep behaving as they have in the past.....the sun keeps rising and my Gekko keeps behaving the same way. I guess i will just keep diving as I have and keep my eye on my available gas so that if I do have to do a deco stop I have the gas to do it (actually I did incur a deco obligation on one dive....it didnt really present a problem and my Gekko behaved in a predictable manner). I wont push my luck and get split fins, but I might just buy a spare air if I see one cheap enough

 

[DaleC]

I will also avoid absolutist terminology and just say that, as a Suunto user, for the many dives I have done, my computer has behaved consistently the same way; clearing deco and adding NDL as I ascend.

 

[Lorenzoid]

I have seen my Suunto decrease the displayed no-deco time when I have gotten to the ascent line on a deep dive but begun my ascent very slowly--for example, waiting for my buddy to catch up. I believe the algorithm expects you to ascend at approximately 30 fpm, neither much faster nor much slower. My Suunto will also impose a 3-min. deco obligation (in other words, it recharacterizes the optional or no-penalty safety stop into an obligatory stop) if average and/or instantaneous ascent rate exceeds some threshold. If you don't attend to this obligatory stop, it adds still more deco time. This latter feature is explicitly stated in the manual.

 

[aprivetera]

Back again after thinking this through and reading up a bit on the RGBM (just google it). I have had experiences where it has both cleared deco if I manage to go over the NDL for whatever reason and also added more deco than it had previously before. In retrospect it seems that it definately has to do with your repetitive dive profiles. I would venture a guess to say that if you always dive similar profiles, you could probably get it to "clear deco" if that was your objective and you dive the same profiles every time. But I would not count on it to clear deco and I would definately manage my air accordingly, because the model seems to take more than "go up a little bit to get more NDL/less deco" in its algorithm.

 

[cbm32]

Managing ones air is always the watchword of the day, is it not?

 

[AfterDark]

You sound to be very new to diving. The depth limits from your OW course are there for a reason, and you need to inch your way past the 60 ft limit very slowly. You also need to have better redundancy when you go past 60 ft. This means that you must be able to absolutely trust your dive buddy, or have your own redundant air source. If you don't have dives past 80 ft yet, you are definitely not ready for dives past 100 ft. I would recommend not exceeding 80 feet until you get some more dives under your belt, or take a deep diver course. Since you were talking about mult-level diving, that must mean there is something to see at shallower depths. Perhaps you should stick to looking a stuff at those depths. Don't get in over your head, and try to do dives that are beyond your ability.

Olympus won't let him do a dive past 60' withOUT a pony bottle. OP consider this, you may wind up diving a different wreck then you were planning on diving because of the weather. I used 21% for my dives because from day to day we didn't really know where we'd be diving. I dove with Olympus last week. We stopped at the Aeolus but dove the SPAR instead. You need to be able to plan on the fly.

 

[Lorenzoid]

Olympus won't let him do a dive past 60' with a pony bottle. . . .

Did you mean to say "without"?