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I looked at boulderjohn's response to DogDiver in which the gas was 32/0. The gas in Boulderjohn's quote in your response somehow got changed to 0/32. That's weird. Boulderjohn must have edited his response after you posted but before I responded.

I interpreted boulderjohn's 32/0 just as he explained it: 32% oxygen, 0% helium, and 68% nitrogen. So, why is it hypoxic?

You would need to display the raw ceiling on the main display in order to appease the computer. This change could be incorporated to allow divers to decompress following the ceiling where flashing red alarms for bypassing staged stops would be unnecessary and annoying. However, there might be...

I don't think it matters much in regards to safe off gassing, but you may end up getting locked out of your computer for those using recreational dive computers, when you disregard a scheduled deco stop.

If you need to add or release air from your BCD do it in short bursts and wait a few seconds. There is a delay in the buoyancy change.

I've felt dizzy occasionally when ascending. It lasts only for a few seconds and doesn't happen on all dives. The Chairman is probably right in that it is an imbalance in pressure between the two ears. I've had a reverse squeeze in the past and fortunately it didn't result in a punctured or...

If your computer has a pressure sensor and it is with you (you don't have to wear it) it may not know your current tissue saturation level unless it stores the last levels (which most if not all computers do). It also needs to constantly calculate the tissue pressures and store the results at...

Based on emoreira's and post #22 I would say the point is if you don't care about the warranty or if the warranty has expired go ahead and change the battery yourself. If you do care or you are all thumbs then send the computer in and have a certified technician do it.

While we don't have access to the exact algorithms employed in the dive computers, Bruce Wienke wrote a paper on the RGBM model. It is included below. Beyond all the initial pages on the math he has some interesting comments at the end of the paper.

While some slow TC's (tissue compartments) on gas, especially during deep deco stops , they may not on gas to the point of being the CTC (controlling tissue compartment). The amount of on gassing is partly controlled by the TC's half-time. Since TC's 14,15, and 16 have such long ht's they...

One interesting point is that the process I describe above continues on the surface. Once the TC's have saturated at ambient pressure the computer probably stops calculating TC pressures and ceilings until there is a substantial ambient pressure change (ex. ascending to lower pressures or...

I don't have access to Suunto's dive computer code. Most, if not all, the commercial personal dive computer algorithms are proprietary and are not available for scrutiny. I can tell you how Erik Baker's (Fortran) and my Excel spreadsheet (VBA) work as these programs are in the public domain...

If you put your mouth over the valve that could happen. We were told to breath from the bubble stream; your mouth did not touch any part of the valve. I know it's weird but it works. You would think you would get water forced into your lungs but you are over the valve so the water does not get...

I wasn't thinking of bubble growth. However, a lot of the inert gas bubbles have been washed out by the O2. I read something about oxygen DCS. Has this happened? Is it true? Or, is it something theoretical?

Wow! 1 fpm. That seems agonizingly slow and agonizingly unnecessary. I don't dive with pure O2 but I think once you're cleared to go to the surface you stay on O2 all the way up. Since you're not taking on any inert gas what's the point of making such a slow ascent? Edit: I posted this before...

I got certified (Basic, not OW) in 1974 from NASDS. As part of getting certified we had to do exercises that would make the SEAL's proud. With all of our equipment scattered at the bottom of a 12 ft pool, we had to dive to the bottom, assemble our equipment and put it on, before going to the...

Using my spreadsheet I compared two dives, both to 250 ft for 20 min, at a descent rate of 60 fpm, using a GF of 60/85 on trimix 20/40. One dive used an ascent rate of 30 fpm for the entire dive. The second dive used an ascent rate of 120 fpm up to 100 ft which was the first stop and then 30 fpm...

Your example above highlights the issue with reverse profile dives, that they are inefficient. If you need time (i.e. more NDL) at the deeper depth you need to do the deeper dive first. PADI understood this but as time went on the admonition to avoid reverse profiles became stronger until...

I don't think I would want to get close enough to stick this knife into them if that is even possible. I would prefer something longer like a bang stick. The ad for the knife says it's useful against large land predators like bears. Again, I don't want to be that close. My advice: get a gun.

In today's highly charged political climate AAA must stand for: A(nd) yet A(nother) A(ctivist) We need to protest that there are too many firefighters standing in the way of oncoming cars. :wink: