Under Federal Law, Which Type of Boat Must Have a Capacity Plate?

The answer

Federal law, enforced through U.S. Coast Guard construction standards, requires that monohull powerboats under 20 feet in length, manufactured after November 1, 1972, carry a permanently attached capacity plate. The plate is installed by the manufacturer, usually near the helm or in clear view of the operator, and it is a legal safety document — not just a suggestion.

The key word is powerboat. The rule targets small, motor-driven monohull vessels because they are the boats most likely to be dangerously overloaded by recreational owners who add passengers, gear, and fuel without realizing how quickly weight compromises stability. A boat that sits too low in the water swamps or capsizes far more easily, which is exactly what the capacity plate exists to prevent.

What the plate tells you

A capacity plate lists three critical limits: the maximum number of persons (and their combined weight), the maximum total weight of people, motor, and gear combined, and the maximum horsepower the hull is rated to carry safely. Staying within all three numbers keeps the boat within the design conditions the manufacturer tested. Exceeding them — even on a calm day — is both unsafe and, in most states, a citable violation because overloading is treated as negligent operation.

Why the other options are wrong

Several common vessel types are exempt, and knowing why helps you rule out wrong exam choices:

• Canoes and kayaks are manually propelled, not powered, so the federal powerboat rule does not apply to them.
• Sailboats are excluded because their weight distribution, ballast, and propulsion differ fundamentally from powerboats; the standardized capacity formula was not written for them.
• Personal watercraft (jet skis) are governed by the manufacturer's own operating limits rather than a standard capacity plate.
• Inflatable boats are also exempt from the mandatory plate requirement.
• Boats 20 feet and longer fall outside the "less than 20 feet" threshold, and vessels built before November 1, 1972 predate the regulation.

So a choice like "all boats" or "any sailboat over 26 feet" is incorrect: the requirement is narrowly scoped to small monohull powerboats.

The bigger picture

If your boat has no plate — because it is a canoe, an older hull, or a homemade craft — you are still responsible for not overloading it. The Coast Guard provides a rule of thumb for flat-bottom monohull boats under 20 feet: length (ft) × width (ft) ÷ 15 = number of persons. For a 16-foot boat that is 6 feet wide, that is 96 ÷ 15 ≈ 6 people. Treat that as a ceiling, and reduce it in rough water. The capacity plate simply removes the guesswork by giving you the manufacturer-tested limits directly.