INTERNATIONAL ONLY Which signal is sounded ONLY by a vessel in sight of another and NOT in or near an area of restricted visibility?

Correct Answer: Option A — One short blast on the whistle

COLREGS Rule 34(a) specifies that one short blast is a maneuvering signal used only when vessels are in sight of one another. Conversely, signals for restricted visibility under Rule 35 are used in or near areas of limited visibility and involve prolonged blasts, not short blasts.