Originally Posted By: dougwalkabout

Depending on the situation, police from the local jurisdiction could conceivably be stationed on the land end of the gangplank.

I think the coast guard has sole jurisdiction over ships at sea. wildman will know how it actually works but I assume the local coast guard commander has the last word on what happens.

There was an incident during Sandy when a cruise ship was refused permission to enter port and disembark passengers ahead of the storm: the coast guard commander judged it already too dangerous to disembark passengers and ordered the cruise ship back out to sea to ride out the weather there.