A vessel is proceeding at 14 knots in 400m visibility. A senior officer says "safe speed is 6 knots here." The master says "we need 14 knots to make our ETA." Who is right and why?

A. SAFE SPEED ANALYSIS — 400M VISIBILITY AT 14 KNOTS: COLREG RULE 6 FACTORS for safe speed: (1) Visibility — 400m is severely restricted; (2) Traffic density; (3) Manoeuvring ability and stopping distance. STOPPING DISTANCE AT 14 KNOTS: a typical large vessel at 14 knots requires 10-15 ship-lengths to stop (crash stop). For a 150m vessel, that is approximately 1500-2250m — FIVE TO SIX TIMES the 400m visibility range. THE ANSWER: the senior officer is correct. Safe speed means the vessel must be able to take effective action to avoid collision and stop within an appropriate distance. At 14 knots with 400m visibility, the vessel CANNOT stop before reaching a contact that appears at the limit of visibility. COMMERCIAL PRESSURE vs SAFETY: the master's ETA argument does not override COLREG. Commercial pressure is NOT a factor in the Rule 6 assessment. COLREG Rule 6 factors are: visibility, traffic density, manoeuvring ability (power/stopping distance), background lighting, proximity of navigational hazards, draught. ETA is not listed. LEGAL POSITION: if a collision occurs at 14 knots in 400m visibility, the OOW and master face a negligence finding — excessive speed is clear. THE OOW'S DUTY: if ordered to maintain unsafe speed, the OOW should record the master's instruction in the log and may ultimately invoke their right to refuse an unsafe order.

B. The master is right — ETA obligations are a SOLAS requirement under Voyage Planning. Commercial commitments are a legitimate Rule 6 factor that balance against visibility.

C. Safe speed in fog is exactly half the service speed. At 14 knots service speed, 7 knots is automatically the Rule 6-compliant safe speed.

D. Safe speed only applies when another vessel is detected on radar. At 400m visibility with no radar contacts, the vessel may proceed at full speed.

A. COLREG RULE 19 — CONDUCT IN RESTRICTED VISIBILITY: Rule 19 applies to ANY vessel not in sight of another. Key requirements: (1) RULE 19(b) — SAFE SPEED: proceed at a safe speed adapted to prevailing circumstances and restricted visibility. The vessel must be able to take proper and effective action to avoid collision, and stop within an appropriate distance; (2) RULE 19(c) — RADAR: have due regard to prevailing circumstances, including the limitations of radar equipment; (3) RULE 19(d) — RADAR-ONLY CONTACT: a vessel that detects by radar only another vessel shall determine if a close-quarters situation is developing. If so — take early, substantial avoiding action: (i) an alteration of course to port for a vessel forward of the beam is to be AVOIDED (except when overtaking); (ii) avoid altering course toward a vessel abeam or abaft the beam; (4) RULE 19(e) — SOUND SIGNAL WARNING: if a sound signal is heard apparently forward of the beam and its vessel cannot be seen — reduce to minimum speed or stop. Take all way off if necessary; (5) RULE 35 — FOG SIGNALS: one prolonged blast (4-6 seconds) every 2 minutes when underway making way. Two prolonged blasts (2-second interval) every 2 minutes when underway but stopped. RULE 19 DOES NOT APPLY RULES 11-18 (in-sight rules). There is no give-way/stand-on in restricted visibility. All vessels take action to avoid collision.

B. Rule 19 suspends all other COLREG rules in fog. No vessel has right of way in fog, and any vessel may alter course in any direction to avoid collision.

C. Rule 19 requires vessels in restricted visibility to stop and anchor until visibility improves to at least 1nm before proceeding.

D. In restricted visibility, the stand-on vessel (Rule 17) must maintain course and speed even in fog. Rule 19 only applies to give-way vessels.

A. RULE 35 FOG SIGNALS — CORRECT SIGNALS: (a) POWER VESSEL UNDERWAY MAKING WAY (Rule 35a): ONE prolonged blast (4-6 seconds) — every 2 minutes; (b) POWER VESSEL UNDERWAY BUT STOPPED (Rule 35b): TWO prolonged blasts with 2-second interval — every 2 minutes; (c) VESSEL AT ANCHOR (Rule 35g): rapid ringing of bell for approximately 5 seconds — every 1 minute. Vessels of 100m+ ALSO sound a gong aft for 5 seconds after the bell. A vessel at anchor MAY ALSO sound "short-long-short" (Morse R —. — .) as a warning to approaching vessels; (d) VESSEL AGROUND (Rule 35h): three separate bell strokes, THEN rapid ringing of bell for 5 seconds, THEN three separate bell strokes — every 1 minute. This sequence distinguishes a vessel aground from one merely at anchor. ADDITIONAL SIGNALS: sailing vessel under sail — Rule 35c: one prolonged + two short blasts every 2 minutes (this same signal is also used by vessels restricted in ability to manoeuvre, constrained by draught, not under command, and towing/being towed — Rule 35d/e); pilot vessel — Rule 35g: normal fog signal + four short blasts as identity signal.

B. All vessels in restricted visibility sound one prolonged blast every 2 minutes regardless of their status. Rule 35 makes no distinction between underway, stopped, or at anchor.

C. A vessel at anchor does not need to sound fog signals provided she has all-round white anchor lights displayed and is monitoring VHF Ch 16.

D. Two short blasts is the correct fog signal for a power vessel underway making way. One prolonged blast is used only by sailing vessels.