Long hair can become a tangled mess when scuba diving.
Just ask my wife.
I’ve watched my wife wage war with her hair before, during, and after our dives. I’ve seen her destroy pony-tail holders. She’s tied her hair and mask strap together in such a complex knot; I honestly thought I’d need a razor blade to cut it out. There have been days where her post-dive hairdo resembled something you might have seen at a ‘Flock of Seagulls’ show.
….I might get in trouble for that last one….
Anyway, the point is this: girls and guys with long hair can have a mess on their hands every time they go diving, unless they know how to keep it under control.