If there were some fishermen standing around, and happen to see someone trying to steal a boat motor. Maybe the fishermen could talk the thief into going fishing.
While fishing you could stop by a far off
un populated island. Some times people can't find there way back to the boat,and sometimes people get left behind. The right thing to do then would be to contact the police and tell them you lost your fishing partner on the island. I would do this in a promt maner. Two, three days max.

I wish, this would never happen in the real world. To many bleeding hearts.