Need not show any lights is true for a vessel of less than 20 meters in length at anchor at night in a "special anchorage area designated by the Secretary"
Step-by-step explanation:
In the INTERNATIONAL— Lights and Shapes under RULE 30 named "Anchored Vessels and Vessels Aground" there are several rules listed. For a vessel of fewer than 20 meters in distance, when at staff in a special anchorage zone assigned by the Secretary, shall not be expected to show the anchor lights and shapes needed by this Rule.
Suppose a vessel of fewer than 12 meters in the distance when grounded shall not be wanted to display the lights or shapes. When a vessel of fewer than 7 meters in length, when at staff, not in or near a restricted channel, fairway or anchorage, or where other vessels normally travel, shall not be wanted to show the lights or shape.