§178.320. Intact stability requirements—non-sailing vessels.

Monohull vessels; and

The vessel carries not more than 49 passengers and does not make international voyages;

The vessel operates on Protected Waters only;

The vessel is constructed with only one deck;

The buoyant hull volume consists of two symmetric, fully enclosed hulls;

The cross section of each hull is circular or of wall-sided construction without tumblehome, and constant for at least 90 percent of the length of the hull;

The hulls contain no machinery or tanks;

There is no deck more than 0.15 meters (6 inches) above any point on any of the buoyant hulls;

The distance between the centerlines of the hulls is not less than 1.83 meters (6 feet); and

Each hull has a beam or diameter, as applicable, of not less than 0.61 meters (2 feet).

Dispense with the requirements of the simplified stability proof test in § 178.330 or § 178.340 of this part when the vessel's stability can be adequately assessed by alternate means giving due consideration to each item that impacts a vessel's stability characteristics which include, but are not limited to, the form, arrangement, construction, number of decks, route, and operating restrictions of the vessel; or

Authorize a change in the requirements of the simplified stability proof test in either § 178.330 or § 178.340 of this part, when necessary to adequately assess the vessel's stability.