Yeah, mask straps do tear my hair, no matter what kind I get, but not when the strap is over the beanie. But if I dive without the beanie, my hair will get so tangled that I can't comb it out with any sort of product without tearing it.
I'm talking about those dorkie neoprene beanies with a chin strap that Henderson and others sell.
Microprene 2® Tropic Hood I've tried scap caps, lycra caps, all sorts of things, and they won't stay on my head. My hair is pretty slick, so the sexy Henderson beanie with chin strap was the only thing that worked. Anything in your hair will probably rinse out over a dive, but if it is wet prior to the dive, the hair shaft won't be able to absorb as much salt. Mine seems to be holding up better now that I wet it or put something wet in it first.
Let us know how that swim cap works. The regular rubber ones that I use for lap swimming aren't going to stay on me in the ocean. But the one you linked to is porous, right?... and may stay on a bit better.