Advances in
saturation diving during the last few decades have allowed a
dangerous and extremely freaky profession to '
surface'.
Pardon the pun.
The Comex company currently employs divers to live on the bottom of the sea, often as deep as 470m for as long as a few months, to lay oil pipes. These divers employ special techniques to keep their blood saturated(see saturation diving) with helium, and in doing so eliminate their need to decompress and risk the bends. Divers doing this can live on the sea floor for months at a time, laying pipes during their waking hours and returing to a 'Deep Sea Habitat' to sleep and eat.
If the idea of living like this doesn't frighten you, nothing will.
Imagine life on the sea floor, in total darkness, laying pipes under extreme pressure. To top it off, every diver's voice is screwed up during saturation diving because of the oxygen-helium mixture that they breath.
I guess it takes all sorts...