There are two distinct kinds of charter boats that take people deep sea fishing. The first is a six passenger boat. Six passenger boats are properly named uninspected passenger vessels. Most people call them six pack boats because the operator may not take more than 6 passengers for hire. The second is an Inspected passenger vessel. Inspected vessels are also called multi-passenger vessels, may only carry the number of people that the U.S. Coast Guard says they can carry. This number is on the inspected boats "COI" or Certificate of Inspection. When you are reading websites and you see boat that says it can carry 40 passengers, that means that is the number of people their COI allows them to carry.