Unsettling or scary books about the sea, diving, shipwrecks,…

Can anyone recommend creepy and unsettling books that involve deep water, diving, the ocean, maybe deep sea or cave exploration, shipwrecks or anything of the sort? I enjoy horror media and have always had a fascination with these subjects. Outright scary and/or gory stuff is also welcome, but I'm especially interested in anything that creates a sense of unease and creeping dread. Bonus points for psychological aspects to the horrors.

I've yet to find anything that scratches that particular itch. I was very hyped for "Our wives under the sea" by Julia Armfield, but I'm afraid it ended up not being quite what I was looking for.