Hijacking the thread a little here, but I remember hearing back when i was in SF that the pilot boats there could be operated by somebody without a license. The word was that lots (all?) of the operators had tickets, but that it wasn't technically a requirement for the job. The notion was that since they only carried pilots, who were all owners, not passengers, they didn't need a license. Or something like that.
This could be totally made up, but thought i'd throw it out there, see if anyone else has heard about it.