I also have a type of dream occasionally, in which I dream I'm dying. Usually I'm under water, and for some reason can't reach the surface anymore (dive too deep, legs caught in something, swimming up frantically but not making any progress, ...). I panic because I'm suffocating, and finally give up, resigning to die, and breathe the water in. Then to my amazement, I find I can breathe water! I'm very happy, and enjoy breathing underwater for a few seconds, then I wake up. This always happens the same way, and when I'm awake again I know "ah, that dream again". During the dream I never remember having dreamt or experienced this before. Perhaps it's a sort of sleep-apnea (
http://en.wikipedia.org/wiki/Apnea_vera), but I don't know.
Anyone else with similar experiences?