3.7 Vessel Documentation, Load Lines & Regulations

Key Takeaways

  • An uninspected passenger vessel is under 100 gross tons and carries no more than six passengers, at least one of whom pays for the trip; this is the legal basis of the six-pack license.
  • A vessel of five net tons or more carrying passengers for hire in coastwise trade must be federally documented with a Certificate of Documentation bearing a coastwise endorsement.
  • Load-line (Plimsoll) marks apply to larger oceangoing vessels; a typical small six-pack boat under 79 feet on a domestic voyage is exempt.
  • Negligent operation is a civil penalty, but grossly negligent operation that endangers people is a criminal offense - a class A misdemeanor.
  • Operating a vessel under the influence carries both civil and criminal penalties, with a 0.08 percent blood-alcohol standard for recreational operators.
Last updated: July 2026

What an Uninspected Passenger Vessel Is

The OUPV license exists to define who may operate a specific class of boat. An uninspected passenger vessel (UPV) is, by federal law (46 U.S.C. 2101), a vessel of less than 100 gross tons carrying no more than six passengers, at least one of whom is a passenger for hire. That is the origin of the nickname six-pack. A vessel of 100 gross tons or more may carry up to twelve passengers and still be uninspected, but the small-boat limit is six. "Uninspected" does not mean unregulated - it means the vessel is not subject to the full Certificate of Inspection that a larger "small passenger vessel" needs. It must still meet uninspected-vessel safety-equipment rules and be operated by a licensed operator (OUPV or higher).

Passenger vs. Passenger for Hire

The hinge word is hire. A passenger for hire is someone who has paid consideration - money or its equivalent - as a condition of the voyage, whether paid to the owner, the operator, or a third party, and whether paid before or after the trip. Even one paying passenger turns a pleasure outing into a commercial voyage requiring a licensed operator. "Consideration" is read broadly: a shared expenses arrangement can still count. If you carry six friends and no one pays, no license is required; if one of those six chips in for the charter, you now need your OUPV.

Documentation vs. State Registration

Every vessel has a legal identity. Small recreational boats are usually numbered (registered) by the state. But a vessel of five net tons or more that engages in coastwise trade - which includes carrying passengers for hire between U.S. points - must be federally documented, receiving a Certificate of Documentation (COD) from the U.S. Coast Guard's National Vessel Documentation Center with a coastwise (or registry) endorsement for the trade it is in. A net ton is a measure of internal volume (100 cubic feet per net ton), not weight; most vessels around 25 feet and up measure five net tons or more. A documented vessel carries its official number permanently marked inside the hull and its name and hailing port on the exterior. Larger commercial six-pack boats therefore typically carry a COD; the smallest may operate on state registration where net tonnage is below five.

Load Lines

A load line - the Plimsoll mark on a ship's side - shows the maximum depth to which she may legally be loaded, guaranteeing a minimum freeboard and reserve buoyancy for a given service. Load-line rules, however, are aimed at larger oceangoing vessels. Vessels on purely domestic voyages, and most vessels under 79 feet in length, are exempt from load-line assignment. The practical takeaway for a six-pack operator: your boat almost certainly does not carry load-line marks, but you must understand the concept - loading to preserve adequate freeboard - because overloading a small passenger boat is exactly the stability hazard the marks were invented to prevent.

Negligent and Grossly Negligent Operation

Federal law (46 U.S.C. 2302) puts teeth behind safe operation, and the exam distinguishes the two levels sharply:

  • Negligent operation - operating a vessel in a negligent manner that endangers the life, limb, or property of a person is a civil penalty, up to $5,000 for a recreational vessel and up to $25,000 for any other vessel. Speeding through a mooring field, throwing a dangerous wake, or overloading can all qualify.
  • Grossly negligent operation - operating in a grossly negligent manner that endangers people is a criminal offense, a class A misdemeanor. This is the willful, reckless conduct - operating drunk at speed in a crowded anchorage.

Operating Under the Influence

Boating under the influence (BUI) is prohibited by federal law. An individual operating a vessel while under the influence of alcohol or a dangerous drug is liable for a civil penalty of up to $5,000 and may face criminal penalties as well; the federal blood-alcohol standard for recreational operators is 0.08 percent, and licensed mariners are held to a stricter standard under Coast Guard rules. Alcohol is a factor in a large share of boating fatalities, and a marine-employer chemical test follows any serious marine incident.

Other Duties of the Operator

The master carries continuing legal duties: the duty to render assistance to anyone in danger at sea so far as it can be done without serious danger to your own vessel (46 U.S.C. 2304), and the duty to report a marine casualty - a serious injury, death, grounding, collision, or significant property damage - to the Coast Guard, typically on Form CG-2692.

Scenario. You run day charters in a 34-foot boat that measures 7 net tons and carries up to six paying anglers. Because at least one passenger pays and the boat is under 100 gross tons, you need an OUPV license; because she is over five net tons in coastwise trade, she must be federally documented with a coastwise endorsement. She is under 79 feet on domestic voyages, so no load line is required - but if you crowd all six anglers to one rail and swamp the low stern, you have committed negligent operation, and doing it drunk would be grossly negligent and a crime.

Test Your Knowledge

Which description matches an uninspected passenger vessel under the six-pack rule?

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Test Your Knowledge

A 30-foot boat measuring six net tons carries paying passengers between U.S. ports. What is required for its legal identity?

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B
C
D
Test Your Knowledge

How does the law treat grossly negligent operation of a vessel that endangers people, compared with ordinary negligent operation?

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D