Tug and Yacht

Report Text:

I was motor-sailing within the limits of a harbour.  I saw a vessel on a steady bearing on my port bow exhibiting a green sidelight plus a single steaming light. I stood on. When it became clear that the other vessel – whose size, other than that she was not a large ship, was indeterminate – had no intention of giving way, I swung thirty or forty degrees to port so that we could pass, ‘green to green’.

This policy successfully avoided a collision. The other vessel appeared to continue as though I did not exist, passing fairly close to me and generating such an extreme wash that the deck of my vessel was literally swamped.

Immediately after the incident I ascertained by AIS that the vessel concerned was the tug XXXX. Her owners should be made aware of her conduct. Had my vessel been an open boat, she would have been swamped and very probably sunk.

Lessons Learned: I did all that was required of me by the Colregs. The tug took absolutely no notice of me, despite proper lights being exhibited.  She was not constrained by her draught and had plenty of room for a proper manoeuvre.  I appreciate that there will be emergencies from time to time to which such craft are obliged to respond, but even if this had been the case, she was not released from her duties under the Colregs. I suggest that tugs proceeding in the harbour leave earlier and travel at a speed consistent with their waterline length.

CHIRP Comment:

We contacted the manager of the tug who discussed the incident with the Master of the tug. Whilst this has not thrown light on the underlying reasons for the close-quarters situation, it did reveal that the tug operators believed that their vessel did not produce a large wash.  Whilst the hull form of this modern class of tug may conceivably produce less wash than that of other high powered vessels, the report indicates that it was still sufficient to cause considerable concern to the yachtsman, and, as he says, could have been a major risk to a less robust craft.

We note that the yacht, which was motor-sailing, altered course to port to avoid a collision with the yacht. Let’s look at Rule 17 in full:

ACTION BY STAND-ON Vessel

(a)    (i) Where one of two vessels is to keep out of the way the other shall keep her course and speed.

        (ii) The latter vessel may however take action to avoid collision by her manoeuvre alone, as soon as it becomes apparent to her that the vessel required to keep out of the way is not taking appropriate action in accordance with these Rules.

(b) When, from any cause, the vessel required to keep her course and speed finds herself so close that collision cannot be avoided by the action of the give-way vessel alone, she shall take such action as will best aid to avoid collision.

(c) A power-driven vessel which takes action in a crossing situation in accordance with subparagraph (a)(ii) of this Rule to avoid collision with another power-driven vessel shall, if the circumstances of the case admit, not alter course to port for a vessel on her own port side.

(d) This Rule does not relieve the give-way vessel of her obligation to keep out of the way.

The risk in altering course to port is that if the give-way vessel belatedly alters course to starboard, the two vessels will be turning towards each other.  The normal recommendation for evasive action by the stand-on vessel would be to slow or stop and/or to make a large alteration to starboard, if necessary though 180 or 360°.