Rule 35(k) · Restricted visibility

Pilot vessel identity signal (fog)

Four short blasts — an optional identity signal a pilot vessel on duty may add to her normal fog signal.

You hear: 4 short blasts.

Meaning

“A pilot vessel when engaged on pilotage duty may, in addition to the signals prescribed in paragraphs (a), (b) or (g) of this Rule, sound an identity signal consisting of four short blasts.” It is optional and sounded alongside — not instead of — the normal fog signal.

Key facts

Sounded by
Pilot vessel engaged on pilotage duty
Repeated
Not a repeating signal — sounded when the situation calls for it
Applies under
International & US Inland
Notation
· · · ·

The vessels that sound this signal also show specific lights and day shapes.

Lights & Shapes

Source: Rule 35(k) — USCG Navigation Rules (International & Inland)

Rule text is reproduced from the public-domain USCG Navigation Rules. Audio is synthesized to Rule 32 timings.