A very near miss between a yacht and a merchant ship

A yacht at night under sail in light winds with a defective engine experienced a dangerous closest point of approach (CPA) with a merchant vessel. Several issues relating to application of the Collision Regulations (COLREGs) and interaction between large vessels and smaller pleasure craft come to light.

What did the reporters tell us?

A catamaran of some 33 ft was heading north-west for the Scilly Isles at night, making about 2 knots. Visibility was good, the sea state minimal, the yacht’s lights ‘burning brightly’; it was night. The yacht encountered traffic heading south for the Ushant traffic separation scheme (TSS), passing several ships without difficulty. He then observed a ship on his starboard bow, showing him a red navigation light, on a steady bearing by compass. His receive-only AIS system gave the CPA as zero in 6 minutes. A VHF call elicited no response. He shone a bright torch on his sail, slowed his boat, and altered to starboard (head to wind). The ship passed so close that he could – in his words – “feel the spray from his propeller as he passed”. A VHF exchange then occurred; the other vessel stated he had not seen the yacht’s light, and that the yacht had not been seen on radar.

What did the merchant ship’s company tell us?

The company carried out a detailed investigation which was shared with CHIRP. Key observations include the following: that the ship denied they had received a DSC call; and that the ship’s two watch keepers did not see any lights until sighting a red light at about 2 cables when the yacht was already abaft the port beam and drawing left. This was at about the same time as the VHF exchange between the two vessels took place. The company denied any failure of watch keeping, and pointed to some discrepancy in the positions reported (as evidenced by an ECDIS/ARPA screen shot).

The lessons to be learnt

COLREGs. The merchant ship did not detect the yacht. The reporter stated “I should have anticipated his lack of response earlier”; CHIRP agrees. As soon as it becomes apparent onboard a stand-on vessel that a give-way vessel ‘is not taking appropriate action in compliance with the COLREGS’, she is empowered to take the necessary avoiding action, as always ‘positive and ample’. The yacht’s manoeuvrability was very limited. An early action to put the ship on her port bow would have removed the existing danger. Ushant is a notoriously dangerous crossing point; it would have been prudent for the yacht to have her engine available, especially in light airs.

 The detectability of yachts. We imply no criticism of the reporter in emphasising that many factors may make a yacht difficult to detect from the bridge of a ship which may also have to take action to manoeuvre while still at considerable distance. Many passive reflectors produce a poor return even in good conditions. The yacht’s lights may be relatively dim, appear intermittent, and be indistinct against background lights. The tricolour at the masthead, normally used when yachts are under sail, may be only intermittently visible by virtue of lower brightness and/or the violent swinging motion of the masthead which may easily travel through 60 degrees athwartships and 40 degrees fore and aft in a seaway. The diagram below demonstrates this.


The risk of not seeing a yacht’s lights in a seaway  –Grateful thanks to Captain Dennis Barber (member, CHIRP Maritime Advisory Board) for this diagram

In such conditions, yacht lights can appear as flashes on the bridge of a ship, and therefore be easily missed; they may also, given relative heights, be seen from a bridge at horizon level, giving the impression of a vessel at considerable distance. When suddenly the bearing and position of such a light starts to move rapidly, it is likely to be far too late to take evasive action.

The picture from the bridge of a ship. We imply no criticism of the ship in this case in stressing the need for an alert visual lookout. There have been cases where bright instrument lights at the front of bridges, together with an array of technical information sources, can distract the OOW from this primary duty. If, for example, it becomes a habit to rely on AIS to detect vessels and assess CPAs, by definition smaller vessels not obliged to carry AIS transmitters will not be detected.

The reporter has decided to fit a transmit and receive AIS system. This may be becoming an increasingly wise step to take, especially in busy shipping areas.

The use of radio/AIS. The UK Maritime and Coastguard Agency (MCA) provides clear operational guidance on the use of VHF radio and AIS at sea. The two key points are: (1) although the use of VHF radio may be justified on occasion as a collision avoidance aid, the provisions of the COLREGs should remain uppermost (see the next article); and (2) there is no provision in the COLREGS for the use of AIS information; decisions should therefore be based primarily on visual and/or radar information.

CHIRP Suggests

A yacht may be very hard to detect at night and in bad weather; if in doubt, assume you haven’t been. Fit high power (eg LED) lighting conforming to COLREG stipulations where you can, consider burning normal navigation lights in place of the masthead tricolour, and take positive and ample measures in good time to avoid collision in accordance with the COLREGS if the need becomes obvious. If illuminating a sail, continue (if possible) for an extended period. Passive radar reflectors are unreliable; yachts should consider fitting active reflectors. In ships, remember there are vessels at sea which are not required to transmit AIS data, even if they can receive. In any event collision avoidance decisions should be based primarily on visual and/or radar information. All vessels should avoid buying up precious time communicating (or trying to do so) on VHF. See the next article.