The Bermuda Triangle and Quicksand. Need instant drama, but don't have the time to craft something bespoke? Drop them in either one - quicksand or the triangle - it's like magic, the average TV viewer's brain has been starved for oxygen for so long they'll happily accept either as plausible.
I vaguely recall that as one of the explanations for why they have not found all the wrecks in the triangle- the sea floor there is underwater quicksand
Also incidents at sea are far less likely to be mysterious, with any plane or ship likely to be in that area can actually connect with someone. Versus before when you had no easy to reasonably notify anyone if you were in distress.