Tipping in The Navassa Island is probably the last thing on your list of things to worry about. In fact, if you got to the island as a tourist you would have a story to tell! The island is owned by the United States and is looked after by the Fish and Wildlife Service. You won’t be able to visit unless you are part of the military or a research group.
If you do get the opportunity to go the tipping wouldn’t be a concern! There isn’t any services on the island and it is uninhabited. Have fun though! Its a once in a life time experience!