I too have noticed similar stories starting around 2006. IIRC, this coincides with the release of Carl Hiaasen’s book, Skinny Dip. In it, a husband attempts to murder his wife by flinging her over a cruise ship handrail one night. It’s a wonderfully entertaining read (she survives to exact revenge), but I suggest it has given a few folks like minded ideas.
That's odd. I had just figured that cruise ship deaths weren't on my radar screen before I started planning a cruise myself. I suspect a more likely explanation would be that cruises were getting cheap enough that those inclined to be drunken fools could more easily afford them.
I've read that book! LOL! I do think that most cases have turned out to be accidental drunken incidents instead of murder.