About 12' into the dive, as I grabbed my SPG to check my remaining air pressure for the third time or so, it suddenly started to release a constant stream of bubbles. Miguel being right in front of me, I gave him the emergency signal, whereupon he immediately turned around, saw the problem and quickly shut off my left tank and thereby my back-up regulator with the failing SPG. After that we of course swam straight for the exit. Hadn't he been right there, I would of course have shut off the valve myself, though not quite as fast and I would most probably have silted up the tunnel in the process.
At first I thought my SPG had somehow just unscrewed itself from the HP hose, there was no doubt however once I took the SPG apart in the dive center: a piece had broken off from one of the two tiny O-rings! How? Old and/or not properly lubricated O-ring plus friction could be one explanation, but who knows.
One thing's sure though: That's already the third regulator related issue on this trip (2nd stage elbow O-ring failure, free-flowing 2nd stage and now SPG O-ring failure). And that right after having had my regulators serviced & checked by Tauchsport Manta in Munich. I guess they really didn't want to see me back again. Well, they won't.
UPDATE: Check out gear maintenance for even more troubling info.
