Uninspected passenger vessel: You are going on a boat with a licensed captain, but the vessel has never been inspected by the Coat Guard. At least one of the passengers is paying as a "passenger for hire." The boat can likely only carry six people. This is the most common type of charter when going on a fishing charter.
Passenger for hire: You’re paying to be onboard a boat, which makes it so certain laws have to be followed that help protect you.
Inspected passenger vessel: Your captain is manning a boat that is allowed to take on more than six people. The boat has a certificate of inspection that shows when the Coast Guard last looked at the boat. You are a passenger for hire and are not taking on any added liability because you are not in charge of the vessel.
Source: Tampa Bay Times "Murky Waters: Chartering the wrong boat can have tragic consequences" by Sara DiNatale, November 23, 2017