And by the way - SPOILER ALERT - water is....(anticipation builds) WET!!!
Do you have proof of that?
Vampires sleeping; well the traditions vary but D&D seems to mainly use the Gothic vampire template as made famous by Bram Stoker, so our vampires 'should' be sleeping in coffins during the day, on their mother earth. Astarion is different, of course, and so we don't really know what his sleeping arrangements are. Maybe he is indulging in elven reverie now that his vampiric habits are all confused, or maybe he is just passing time until everyone wakes up.
Hanging upside-down from a tree would be hilarious.
