I have been using this app called Raft Up. It is basically a social boating app (sorta like Waze but for the water).There is also a handy SOS function to notify nearby people if you need help while out on the water. It only really is useful though if a good number of people use it! I think it has big potential if it becomes widely used in the area!
www.raftup.com/site
If this kind of post isnt allowed feel free to remove! I think it could help boaters out though!