Standard dinghy will not pull a tube fast enough (if at all) for a teenage boy. I think the Water Sports Centre at Leverick Bay in the North Sound has a MasterCraft skiboat for rent, with equipment for skiers, tubers and wakeboarders. (I saw somebody's Mastercraft at the dock there in June.) I would echo the rest of what George said, and add that our grandkids, including a 15 year old, enjoyed snorkeling over the Kodiak / Krakon near Mountain Point.