One of the most common questions that arises during a response to a ship incident is the question of who has jurisdiction? The first question that must be answered is in response to the nationality of the vessel, or more commonly "What is its flag?"
The flag is the country where the vessel is registered. It is most commonly determined by looking at the stern of the vessel to see the homeport as well as the flag it is flying. The flag state is the country it is registered in. For example, the M/V Clipper Mermaid that recently had the fire was registered in the Bahamas and the flag state would be the Bahamian Government. Don't be fooled if the vessel is flying the U.S. ensign from it mast. This is a courtesy flag that is flown in the country the vessel is currently in and NOT the flag of the vessel itself. If it is anything other than a U.S. Flag vessel, chances are that you DO NOT have jurisdiction as you would if it were a building or company in your local.
Who does have jurisdiction? A foreign flag vessel is very similar to a foreign Embassy on U.S. soil. There is a certain amount of sovereignty that limits U.S. personal access. That is why the master of the vessel may have the right to refuse or limit your access to his vessel. There are several federal agencies such the Coast Guard, Customs and Boarder Protection and Immigrations and Customs Enforcement that have some jurisdiction over the vessel. If the vessel is on fire, however, the agency most critical to your successful operation is the U.S. Coast Guard.
A Unified Command (that's one of those components of NIMS ICS that you may have recently encountered) may be critical to the successful outcome of this event. The Coast Guard has the authority to direct the vessel and it's crew to ensure the safety and security of the port. The timely notification of the Coast Guard by fireboard is critical to effecting a rapid response by the Coast Guard. In addition, the Maritime Incident Response Team can provide support during your incident including liaisoning with the ship's crew if desired. Jurisdiction and other important response information is covered in the Marine Fire Fighting Level I and V coures.