I was wrestling with this issue too when planning a week long dive trip. I'm a new diver, and although I already used the neoprene mask strap the hair past that strap (at temples) was still getting ripped and the length of my hair was a rats nest using a braided ponytail. I have long curly hair. This trip I did the following:
- wet hair and put leave in conditioner/morrocan oil combo on it. took spray bottle of same in dive bag on boat for post dive spritz.
- used neoprene mask strap
- used thin, wide bungee corded "swimband" headband (protected hairline all around from mask strap and kept skirt clear of stray hair)
- put hair in a very chic Pebbles Flintstone top of head pony tail
- banded length of ponytail with every inch or so with no pull fabric covered elastics. It winds up looking segmented.
- wound the banded length around the elastic closest to my head (first one put in/top of pony) and secured with a scrunchie. Yes, a scrunchie lol, but it NEVER got tangled and kept hair where I put it. Winds up being a bumpy bun on top of head.
- When it was time to take hair down slathered conditioner, removed elastics carefully, rinsed, and used "Tangle Teezer" to brush through. I thought the tangle teezer brush was a gimmick, but it was fantastic, way better than wide tooth comb I used to use.
My hair and color survived a week of diving at AKR quite nicely. I also used hair sunscreen spray when not diving. I used Phytoplage Protective Sun Veil, but I also like the cheaper Proganix Anti-Fade Weightless Argan Oil + UV Protection.