You don't find a trap, but you do realize very quickly that the lock has been augmented by Arcane Lock and that the chest has had some magical waterproofing applied to it. You are able to get through the augmented lock as as if it wasn't even there, and are able to open the chest. Inside, you see the belongings of a traveling magician. There is a nice suit with matching top hat, a variety of props, most of which have been modified to assist in various tricks, and numerous other personal belongings. When you open the chest, the magic on the chest itself disappears, apparently a temporary application to protect it on the ship ride. You figure that the man who owned it has been turned into dinner by either the hag or the goblins by now. The top hat and one of a pair of matching batons glows with faint magic as does a real pearl on a string of nice looking, but mostly fake pearls wrapped around the top hat.