The motor ship Jacks Or Better became disabled off Mayport, Florida.   The chatter casino vessel was proceeding back to Mayport with 60 passengers on board when it lost propulsion.  The crew contacted the Coast Guard who responded sending the 45-foot rescue boat to its aid.  A commercial tug also responded, but was not needed.   The Jacks Or Better was able make repairs and proceeded safely to port a few hours later.  No reports of injuries, damage or pollution being released.