I've noticed that this type of thing seems to polarize things rather than bring people together. Dialog between groups is a good thing, especially out on a boat where someone can't say F(*K You and walk away.
Another option Doc, take anyone fishing, just make them sign up to get the ride back to the launch . .. . . $25 or a swim, which will it be .. .. . except Todd, I hear he walks on water. . . . . .