Two points: One, I don't know who you're looking at! They look very, very similar to me. Keep in mind, you have to age your mental image of JWM about ten years. Second, it's absolutely clear that MH wanted to "go missing" / be untraceable. If I were to accomplish that, the best way to do so would be to fake some sort of accident... like a mishap at sea (so that people believe you to be dead). Hence, shrimping boat.