I found this...
Passenger Vessel Services Act
To me, reading this, the Jones Act does not apply to passenger vessels. A similar Act does apply.
My understanding...
Passengers, on the Royal Caribbean cruise that I referenced, would not violate the act if they continue on the cruise to a distant foreign port and the cruise ends where it began. So, if someone is on a Orlando excursion and misses the ship (for any reason, gets injured and has to spend a night in hospital, just late to port, etc.) they would be in violation of the PVSA. If there is a violation, the cruise line is responsible, not the passenger.