Drowning is a means of instantaneous death caused by being submerged in water when you do not have either unbreathing or amphibiousness.
Common forms of drowning are:
- Stepping or falling into water when you have too much encumbrance to escape.
- Falling into water with no adjacent, non-occupied land tile to escape to.
- Being seduced by a nymph while over water and taking off your boots of water walking or levitation. You will NOT attempt to crawl out.
- Being pulled under water by a monster's drowning attack.
If you can teleport, you will attempt to teleport away with a certain probability (before crawling out), provided you have sufficient energy. If you also have teleport control, you always will attempt to.
As a side note, if you have teleportitis, random teleports will only place you in water if you are unbreathing or amphibious.