Marv Gozum wrote: > I'd go for redundancy with a mechanical SPG anyday. The same here. I have seen A/I fail and have looked that the other diver's face as he looked at a blank screen. I personally wouldn't care if the computer fails (backup computer, and I run tables besides). But the spg... well, that's like driving without a gas gauge. Of course the dive is aborted, but since I do a lot of deco diving, I would like to have the spg for air monitoring.