Your mention of salt water damage to hair caught my eye: what sort of damage does it cause? So far I've felt that my hair is "happier" after a week of diving, but then that could be the hardness/softness of the shower water at the lodging, the amount of conditioner I put in it, or some other factor. If saltwater has negative effects, I'd like to know what they are (won't stop diving, but might alter my routines).
I'm still working out what to do with my hair while diving. A single braid or ponytail is great for keeping my mask strap from sliding down, but is continually "bonking" the first stage. One side pony/braid fixed that, but it still gets kind of snarly, and - worse - removing/replacing my mask is a real pain due to stray hair.
I've also read that conditioner is harmful to the reefs, so I've only been putting conditioner in after diving and before combing my hair out/showering (very helpful). Is that a myth?
I've just got a small neoprene beanie - will see how that works. I haven't figured out yet whether I'll try to cram my hair into it, or braid it below.
Since I will also probably want to wear a full hood at some point in time, I'll be keeping an eye on this thread.