The word “Port” comes from “Portus.” In Latin, that word essentially means “haven” or “harbor,” both of which can be synonymous with a “port.” A port is a place where you can dock your vessel, where you are safe from the threats of the ocean, and so forth.  A “hailing port,” then, is, in the context of USCG vessel documentation, the place from which the vessel can claim origin. It does not matter where this is (indeed, the location does not have to be coastal or close to any body of water). This hailing port can be a location of the vessel owner’s choosing, so long as it is a place in the United States that’s included in the U.S. Department of Commerce’s Federal Information Processing Standards Publication 55DC.”  A vessel owner can change their hailing port as well as their vessel name using this form.  A vessel can owner can use this form to apply for initial US vessel documentation, choosing a hailing port there.