The September 1996 issue of the Journal has an article by J. C. Hines which, as a RYA instructor and former maritime lawyer, I found very confusing.

I agree with him that there are many yachtsmen and some professionals who I would not let out in a pram dinghy, let alone in the vessels they are commanding.

It is significant that many commercial ships will have one watchkeeping officer on the bridge, no other lookout, and a helmsman on call. The ship will be on autopilot and, upon a target being seen, it will take two minutes or so before the helm is manned.

I am disturbed by Perkins and Redfern's paper in the May 1996 Journal.

The COLREGS have been developed over many years of tinkering and tuning. They are not designed only for educated European masters driving big merchant ships. The users; fishermen, yachtsmen, oarsmen, tugmasters, Rhine bargemasters, and Yangtse junkmen, etc, are from all educational standards and from all the world's cultures. The COLREGS are now well-known. There is such a huge investment of time and effort, of learning by millions of different people, that the prospect of tampering with their fundamentals is horrific, even if it would suit a small class of user belonging to the more advanced countries. Change is painful, and too much change, too fast, kills. Compare the practical decision not to change the side of the road on which we British drive: it might be convenient, but it would cost too much. The same applies to the COLREGS.

There are two places where landsmen and seamen are likely to come into conflict: (i) in the pubs around Portsmouth Docks; and (ii) in tidal estuaries such as the Thames. There is, however, an intermediate class of person, represented nowadays almost entirely by more or less amateur oarsmen and women, which is that of watermen. I am proud to consider myself a member of all three.

May I congratulate Chris Perkins and Tony Redfern for their excellent paper in the May issue of the Journal. For many years I have read in the Journal, and on occasions listened to, learned ladies and gentlemen discoursing on the subjects of safe navigation and collision avoidance. Also to what I believe are their misguided wanderings into ‘ship domains’ and assumptions that ships behave as atomic particles. Thus it was very refreshing to read the latest and practical contribution by Chris and Tony. Well done chaps!

Following Dag Pike's earlier paper on this subject I would like to discuss some points and address the problems of collision avoidance with High Speed Vessels within the framework of the present International Regulations for the Prevention of Collisions at Sea (COLREGS). Generally, a valid case for limited modifications to the COLREGS may be presented, but they may not be as wanting as suggested by Mr Pike.

The high seas freedom of navigation, and the lesser rights of transit, archipelagic sea lane and innocent passage applicable in straits used for international navigation, archipelagic sea lanes and the territorial sea respectively, have been said to embrace two notions: ‘one is the right to make progress over the surface of the sea, the other is the duty to make progress only in an orderly way, as to speed, steering, lights and so on – the manner of operation of the right’.

This report summarizes a study of signals for indicating course alterations conducted by the Course Signal Committee of The Mercantile Marine Institute of Japan (President Captain Inazo Ara) as part of the 1995 project entitled ‘Research on Improving Course Signals etc’ sponsored by The Japan Foundation for Shipbuilding Advancement.

It is well known that many collisions occur because one ship turns right whilst the other turns left when in close proximity to one another. Little is known as to why this occurs and, although some simulation models have been established using entropy theory, the problem remains unsolved.

In this paper, an assessment model for uncertainty is reviewed briefly. The concepts of uncertainty and uncoordination of mariners' behaviour in collision avoidance are discussed. A simulation model in conjunction with a DCPA (distance to the closest point of approach) decision-making model using fuzzy programming is introduced to discuss coordination.

Traffic regulations have to be clear and strict. Only then can navigators ran their vessels safely. As a complete set of simple rules cannot be developed and introduced within the next decade, suggestions are made to improve the existing rules.

The risk of a close quarters situation arising when a vessel crosses a busy traffic lane, such as one of the separation lanes in operation in the vicinity of the Dover Strait, is usually assessed in terms of the number of encounters or domain infringements likely to occur if no avoidance action were taken. Such calculations, which are based on the theoretical encounter rate, do not normally take into account any enhancement of the risk which may be associated with the simultaneous interaction of a crossing vessel with more than one other ship.

In this paper, the methods of collision avoidance by radar which have been used in the radar simulator course at Chinese marine colleges are introduced. Then some other methods of estimating the risk of collision, safe passing distance and course alteration in radar collision avoidance are presented.

A new threat detection criterion is described which provides a better match to the requirements than the well-known modified tau criterion for a civil air transport collision avoidance system. Experimental evidence is given to show that it also reduces the number of undesirable alerts.

The views expressed in this paper are those of the author and do not necessarily represent CAA policy.

The author would like to give grateful acknowledgement to the various companies from which information has been received. (Note that the original presentation at a RIN ordinary meeting was illustrated by numerous colour slides which cannot be reproduced here, as well as three video films).