It is a fundamental legal principle in every state in the union that all penal laws (laws that create crimes and misdemeanors) must be strictly interpreted. If a penal law requires that "anchored" vessels must display an
anchor light, then the law doesn''t apply to a
dinghy that is tied to an anchored yacht. Only a “vessel at
anchor” is required to display an all around white light. Strictly speaking, the
dinghy is not "anchored." It is tied to a yacht that is anchored.
Also, if a penal law is capable of two interpretations, then the interpretation must be applied that is most favorable to the citizen, and that is least favorable to the government. In this case, the law is susceptible of being interpreted to apply to a vessel that is anchored to the ground, or to a vessel that is anchored to another vessel. The scope of the law is limited to the former interpretation.
Nevertheless, the hard reality is that, if an inexperienced young assistant government attorney, or a hard-headed old government attorney, interprets the law otherwise, you might have to engage the US government in an expensive legal battle to win your point.
The scope of a penal law can''t be broadened by interpretation. Its meaning is limited to the literal meaning of the words.