When people initially sign up for Nautical Monkey, we put a "test" boat in for them to make it easier to play around and test the system. Sometimes people get confused between the test boat and a real boat that they have been invited to.
In this case, he hadn't actually accepted your request - I manually accepted for him - so should show up as a "member" now on your side.
I also deleted his test boat so he won't be confused between that and the real thing.