Recs if you like The Forgotten Island...

...or the shallow. But either way, don't go near the water.

Aquatic horror

Horror books swimming with thalassophobia

Horror, thrillers, and mysteries where "island escape" doesn't mean a nice vacation

Books of people who die because they go or do something they know they probably shouldn't be doing.

Serial killers Creatures Supernatural

Happy to take any suggestions.