Passing honors are ordered by ships and boats when vessels, embarked officials,
or embarked officers pass (or are passed) close aboard - 600 yards for ships,
400 yards for boats.
Such
honors are exchanged between warship and merchant ships, between ships of the Navy
and the Coast Guard, and between most foreign navy ships passing close
aboard. "Attention" is sounded, and the hand salute is rendered by
all persons in view on deck. Dipping their ensigns is observed between merchant ship and a warship when they pass each other at sea.
