International maritime law and as a consequence all known national maritime laws require that the crew of a ship obey the orders of the captain and his officers (at least as long as they relate to the safety or handling of the ship). This applies to all ships, regardless of their size or designation.
Disobedience in such matters - also called mutiny when done as a group - is a serious crime (in the US, mutiny bears the death penalty).
Disobeying the captain's orders can and probably will also happen on pleasure boats, eg. refusal to wear lifejackets when ordered, deliberately sleeping on watch, getting seriously drunk, etc. Normally, a pleasure boat captain will probably just throw those people out in the next port, but I assume he could also report them to the police, in particular, if the disobedience resulted in an accident. Are there any such cases known? Have there been convictions for disobedience by the crew of a pleasure boat?