Your statement is based upon an extremely narrow interpretation of federal rules. Read 33 CMR 83.03(g). Note the words "but are not limited to". I suspect a 3rd year law student would have no problem convincing a judge that a 274' long vessel weighing 2400 tons has limited maneuverabilty.
"The term vessel restricted in her ability to maneuver means a vessel which, from the nature of her work, is restricted in her ability to maneuver as required by these Rules and is therefore unable to keep out of the way of another vessel. The term vessels restricted in their ability to maneuver include, but are not limited to:
(i) A vessel engaged in laying, servicing, or picking up a navigation mark, submarine cable, or pipeline;
(ii) a vessel engaged in dredging, surveying, or underwater operations;
(iii) a vessel engaged in replenishment or transferring persons, provisions, or cargo while underway;
(iv) a vessel engaged in the launching or recovery of aircraft;
(v) a vessel engaged in mine clearance operations;
(vi) a vessel engaged in a towing operation such as severely restricts the towing vessel and her tow in their ability to deviate from their course."