1. If you're relying on gill growth. That has a relatively short timer - not much over 10 ticks at hero.

2. If you're a mariner without water breathing up and manage to flee underwater and get slept.

3. Same as #2, but if you have the "last breath" edge.

The imms have done a good job of removing most xp draining due to pks. (One "by design" exception would be WANTED flags.) I don't see it as being a big deal to check if the person is unconcious from another player and have them not lose xp. Hell, it would be nice if the person that knocked them out got credit for the pk too.

I'm not sure why they introduced xp loss due to drowning in the first place. I think they may have done it to penalize a common means of ditching flags, but if that's the case, why not just apply the xp penalty only to those who are flagged?