You are on a collision course and the ship should give way. When is the right time to alter course?

James Stevens answers your Questions of Seamanship.

Question: When is the right time to alter course?

Roy owns Boreas, a 12m long-keeled Bermudan cutter.

He bought her because, in his words, she is sea-kindly and stable.

The downside is that Boreas is heavy, difficult to manoeuvre and slow in open seas.

Roy and wife Peggy are sailing from Cherbourg to the Solent.

The wind is northwesterly 4 and Boreas is sailing close- hauled on a port tack at about 4 to 5 knots in good visibility in daylight.

Roy has safely negotiated the shipping off Cherbourg and is now in clear water, north of the Traffic Separation Schemes and about 10 miles from the Isle of Wight.

A small coaster appears on the port bow.

Roy takes bearings of it with the hand- bearing compass.

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The bearings remain constant. Roy knows that in the open sea the coaster should keep clear.

As an additional precaution, Roy has hoisted the octahedral radar reflector so he feels confident that he is visible.

Roy holds his course – he doesn’t want to alter his heading and confuse the coaster which is now less than a mile off.

The two vessels continue on a collision course; Roy decides to tack.

He instructs Peggy to put the helm over and concentrates on the jib and staysail sheets.

In the meantime, the ship has altered course to starboard and is now heading straight for Boreas.

The yacht scrapes the side of the ship, fortunately without serious damage except for a very shaken crew.

What should Roy have done?

James Stevens answers:

Roy is correct in thinking that the coaster should keep clear outside of the Traffic Separation Schemes.

The captain of the coaster also knew that and made the correct alteration of course, to starboard.

The problem is that it all happened too late.

First, it is a good rule of thumb that yachts should, if possible, avoid a situation where a ship is the give way vessel.

This means making a very early decision to tack or bear away and find a large gap in the shipping lane.

James Stevens, author of the Yachtmaster Handbook, spent 10 years as the RYA’s Training Manager and Yachtmaster Chief Examiner

Continuing on a course across the bow of a ship is obviously hazardous.

In this situation, once Boreas was within a mile of the ship, the safest action would have been to bear away and sail parallel to the ship’s course.

This would have given Roy time to work out what the ship was doing and to avoid a collision.

A turn to port in a potential collision situation with a ship is always more hazardous than a turn to starboard.

Roy also took his eye off the ship at the vital moment.

The coaster took the right action but it should have been earlier and more positive to avoid a collision as required by Rule 8 of the International Regulations for Preventing Collisions at Sea.

Collisions between yachts and ships are very rare, particularly in good visibility.

This question is based on a real incident which happened in the Channel 30 years ago.

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