Bonk on the head from behind, and then one good shove over the railing. Adios, chum!
When a person disappears from a cruise ship does their home country investigate? Nope! Police from the country where the ship is registered do the investigation, if one is even performed. Do you think that cop from the Bahamas is going to fly around the world interviewing passengers and collecting evidence? Yeah, me neither.
1. The most likely killer is always the spouse. Guess who will also have the easiest time luring you onto the floating abattoir?
2. Serial killers. I bet it isn’t hard to cruise using a fake identity, not that investigators are ever likely to question you anyway.