This address by the Secretary-General of Imco was given at a meeting of the Institute in London on 10 March 1976, with a Vice-President, Mrs. Mary Pera, in the Chair.

IT gives me great pleasure to be here today and I should like to thank you most warmly for your kind invitation to speak on the work of the Inter-Governmental Maritime Consultative Organization, or IMCO as it is commonly called. Naturally I do not need much encouragement to talk about Imco but I consider this to be a rather special occasion, because of the long and close association between the Royal Institute of Navigation and Imco. I shall advert again and more fully to this association later.

As you know, Imco is a specialized agency of the United Nations charged with important responsibilities in the maritime field. It was established by the Convention on the Inter-Governmental Maritime Consultative Organization, adopted by the United Nations Maritime Conference held in Geneva in 1948. Imco began life in January 1959 and its Headquarters have been in London from that time.

As a result of the loss of the French passenger liner Antilles after grounding on an uncharted rock in the Grenadine Islands in the West Indies, on 8 January 1971, the owners of the ship filed a petition for limitation of or exoneration from liability in the United States District Court for the Southern District of New York. A number of claimants against the owners, chiefly passengers in the ship at the time of loss, entered the limitation proceedings and moved the New York Court to transfer the case to the District of Puerto Rico. After the case had been so transferred, several claimants filed direct action suits against the owners and their insurers; these suits were stayed pending the outcome of the limitation proceedings.

In this paper, which was read at an Institute meeting in London on 11 February 1976 with Mrs. Mary Pera in the Chair, Captain Cockcroft examines the incidence of collisions in relation to the numbers and classes of ships at risk and their trends, pre-war and post-war. Total and partial losses are included and compared with other forms of loss, e.g. strandings.

In several previous papers statistics of marine collisions have been given for particular areas such as the Dover Strait, Western European rivers, the Baltic Sea and Japanese waters. This paper is concerned with worldwide statistics with particular reference to sea collisions. The information is mainly derived from the Statistical Tables published by Lloyd's Register of Shipping and from the casualty reports compiled by the Corporation of Lloyd's. Statistics of shipping casualties must obviously be related to the number or tonnage of vessels at risk; for insurance purposes loss ratios are usually expressed in terms of tonnage lost to tonnage afloat but navigators are more concerned with the number of casualties and number of vessels at risk in various categories.

Many of the tasks which have occupied the navigator ever since measurement and calculation were first applied to the subject are now being carried out or aided by technical devices. This has been going on for a long time, and I would like to consider how far we have got, and what will remain for the concern and interest of our Institute when this technical growth has fully matured.

Historically, radar has been villified as a source of the many accidents, either as collisions or strandings, which have occurred around the world since the end of the war. More truthfully the blame should have been laid not so much on the equipment as on the operator, and it would appear from the many court findings that it is the man who has been unable or perhaps unwilling to extract the level of data needed to navigate his ship successfully from the basic range and bearing information that the radar sensor provides. This shortcoming has been recognized for many years and attempts to correct it have been manifold. There has been heavy investment both by shipowners and education authorities to provide simulators, to offer short courses and to provide anti-collision training, and there has been a marked emphasis on the significance of plotting and radar interpretation in the certificates of competency and D.T.I, examinations. Nevertheless, the lessons which it was hoped would breed good radar practice and which were germinated in the classrooms rarely seemed to come to fruition in the more hostile environment of the ship's bridge. The reasons or the excuse for this lack are not hard to find. There is insufficient space, there is no table, the bridge is single handed, there is too much to do. There are numerous excuses or reasons offered. Many of the arguments are well founded, but these tend only to be a cloak for a more fundamental reason, a reason which is rarely expressed.

It appears that the earliest recorded reference to the effect of the magnetism of a ship or her fittings on the magnetic compass was made by the Portuguese explorer João de Castro in his Roteiro de Lisboa a Goa of 1538. João noticed that the compass he used to observe for variation was affected by iron objects on board placed near to the compass.

Arising from my recent note on short-method nautical astronomical tables, Dr. G. D. Raasveldt of The Netherlands has commented on an elegant solution to the general nautical astronomical problem developed in 1884 by Captain (later Commandant) Emile Guyou of the French Navy. Guyou's method is, indeed, ingenious: it affords an extremely brief solution to the problems of computing hour angle and azimuth given the three sides of the astronomical or PZX triangle. Moreover, by its principles all problems in nautical astronomy may be solved by means of one single-entry table. Sines and cosines, tangents and cotangents, secants and cosecants, versines and haversines—natural and logarithmic—are all made redundant for this purpose by a table whose function is, in general, limited to mercator sailing. This is the common ‘Meridional Parts Table for the Sphere’.

Time is so much a part of everyday experience that no thought is normally given to the meaning of the word. The scientific measurement of a quantity such as time, however, requires the definition of a gauge as a standard of measurement that is reasonably invariant to human experience and the creation of a measurement language capable of independent empirical reproduction so that one laboratory can share experience with another using only a written language to do so.

Time as a means of scientific measurement for navigation requires a further extension of this experience to independent reproduction on a moving craft.

How do Aborigines find their way across the arid wastes of Central Australia? Certainly their feats of practical orientation and tracking are legendary. Are their methods in any way analogous to the non-instrumental arts still surviving in parts of the insular Pacific? (Lewis, 1972). In 1972 the professor of Pacific History at the Australian National University generously extended to Central Australia the accepted bounds of Oceania, to allow me to travel the Simpson Desert with Antikarinya tracker Wintinna Mick in an attempt to find answers to these questions. Subsequently, in 1973 and 1974, a grant from the Australian Institute for Aboriginal Studies and a Visiting Fellowship in Anthropology from the A.N.U. enabled me to extend the investigation into the Western Desert, under the tutelage of men most of whom had spent their youth as nomadic stone age hunters. What they taught me makes up the bulk of this paper and provides some sort of answers to our opening questions.

Chart, compass and log are the three fundamental instruments of navigation. It was not until mediaeval times, coinciding with the early development of these instruments, that navigation became scientific; and certain it is that without them the opening up of the oceans for exploration, as a preliminary to maritime trade, would have been delayed.

The defects of ‘dead reckoning’ navigation, the process by which a vessel's position may be pricked on a chart from compass and log observations, were of little consequence to medieval navigators whose activities were confined to the Mediterranean Sea and the coastal waters of Atlantic Europe. But following the advent of the Golden Age of Discoveries initiated by the Portuguese in the fifteenth century, when western Europeans first struck out to cross the Atlantic, the pressing need for a reliable method of checking DR positions led to the rise of nautical astronomy. The practice of this art which is secondary to the primary navigational aim of finding the way embraces the traditional methods of mathematical astronomy for ascertaining latitude and longitude. A nautical astronomer requires skill, mathematical and scientific expertise and certain indispensable equipment. A chart for pricking position as a preliminary to setting or rectifying a course, mathematical and astronomical tables to facilitate computations and instruments for measuring respectively altitudes and times; these are the main tools of nautical astronomy.

Marine casualties usually arise through a combination of complex conditions. To trace any one of the conditions involved, and its reaction on others, not only helps to reveal the cause of an accident but is also important in understanding the nature of such casualties.

Like accidents on land, marine casualties do not arise spontaneously but have ascertainable causes, rarely a single cause but rather a combination of causes. Thus in a collision in fog in a narrow channel we must consider not only faults in carrying out a manœuvre but also the natural phenomena of fog and the narrowness of the channel.

Recruitment and assessment of the sample. Recruiting and interviewing began in December 1974. Over 220 hours were spent interviewing the sample, which comprised 68 men. Senior officers were preferred because more informed criticism was expected from them. The watchkeeping record of well over two-thirds of the sample amounted to more than ten years' experience; these were masters, chief officers, second officers, uncertificated third officers, senior pilots and, in addition, two lecturers. Many nationalities were represented and the majority held masters' certificates or were attending the college studying for them. The recruitment of serving officers had a rather poor response, numbers being made up by officers on leave. These men came in for a day, a morning or an afternoon, and thus were not exposed to all the systems since such high exposure in a short time might have caused saturation. There was therefore a proportion of the sample which saw only part of the systems though the majority did see it all. There were men who saw just one system, possibly volunteers who did not particularly want to continue, or others who were snatched away from the college by commercial pressures. The approach to these men was important. The sample was exposed to a two-hour lecture period, usually on modern radio aids, and each group was shown the teaching exercises and an explanation of the research objectives as well as the systems.

Two hundred years ago a signal book was issued to a Captain Cornthwaith Ornmary of H.M.S. Tartar. The date was 13 June 1776 and the signal book contained the earliest reference which the author has been able to find to a positive rule of the road at sea. The signal book was the work of Admiral Lord Richard Howe, who in 1776 was commanding a fleet off the coast of north-east America in support of his brother G eneral William Howe. Brother William was enjoying considerable success in 1776 but his contribution to history did not survive his encounters with George Washington in 1777 and 1778. Brother Richard meanwhile, perhaps fortunate in not meeting the counterpart of George Washington at sea, went on to add further illustrious chapters to an already distinguished career. His modest rule of the road has not only survived almost unaltered to the present day but it has also formed the basis for our entire system of rules for preventing collisions between ships.

Traditionally, when some new concept or equipment comes along, one first makes a rough judgment based on a philosophical analysis. If this looks sensible the next step is usually to put the new device to sea and evaluate it there. The early philosophy, the users' reports and a simple economic evaluation usually lead to a sufficiently sound decision. A collision-avoidanoe radar of the new generation presents a substantial philosophical hurdle both to the marine superintendent ashore and to the man at sea, and it represents a fairly substantial capital expenditure. Deciding what is the ‘best buy’ becomes a complex matter for which traditional selection methods may be inadequate. Like others, in our efforts to provide the most useful installation at economic cost, we have attempted sea-trials of some of the new systems. It has proved most difficult to reach objective conclusions, mainly because normal trading does not permit a free choice of encounter situations or manoeuvres, and there is no ‘control’ experiment. In addition, user reports were sometimes dominated by lost confidence due to technical teething troubles. We therefore felt a need to break the problem down into its elements and to attempt a controlled and objective analysis of these elements.

The author, a Master Mariner and Section Chief of the All-Union Research Institute of Marine Fisheries and Oceanography, Moscow, U.S.S.R., deals with the principle of clockwise rotation of the line of relative motion, as applied to simultaneous encounters with several ships. He presents arguments for a strict compliance with the well known dictum of Captain Oudet: ‘Encounters at sea are governed in such a way that each party knows what he should do and what the other should do.’ The paper was written in collaboration with the late Captain G. Shoomayko.

Milford Haven has expanded as a port extremely rapidly over the last few years, largely as the result of a government decision to make it the major deep-water oil port in the country. Between 1959 and 1974 the amount of cargo handled rose from 200,000 to nearly sixty million tons. In this paper, which was presented at an Ordinary Meeting of the Institute held on 19 November 1975 in the City of London Polytechnic with the President in the Chair, the Harbourmaster describes this development, the problems it brought and how they were solved, and some of the lessons learned.

It is commonplace nowadays to assume that modern technology is rendering inevitable the demise of the traditional navigator—in the commercial shipping world at least—and there is much discussion of what this can signify for the future. Yet at the same time there is no little confusion over what is meant, and will be meant, by the term ‘Navigator’. In the context of the Merchant Navy the truism can be made that all deck officers are navigators, and indeed that navigation has been a prime source of satisfaction to many of them; but very few are or ever have been lifetime navigators to the exclusion of all else. Certainly there are the small bands of hydrographers and specific navigators engaged in such fields as offshore work needing a high degree of accuracy, whose prime job in life this is. But they are a select and specialised group whose existence does not negate the view that for the majority of deck officers their navigation is at best part of a wider whole. So to talk of the demise of the navigator is misleading; no deck officers on merchant ships will be out of a job simply because navigation becomes less important. What they will lose is a most interesting part of their work.

There has been considerable progress within the last three years in the evolution of various traffic procedures in coastal and waterway areas. Society at last seems to be awakening to the need for some order and conformity as a means of protecting the marine environment. And sea people have accepted that communications—like steam—have altered the face of the Earth. Learned societies and professional institutions have each played their part on the new frontiers of sea affairs and we have between us not been backward in promoting our ideas as to what the new order could be. We begin to acknowledge that we belong to our times.

We have used the bones of Torrey Canyon and her more recent successors in the Dover, Magellan and Malacca Straits to climb out of an age of obstinate rejection into one of enlightened self-help. Modern life does not tarry with yesterday, and the headlines of past accidents are not necessarily the right titles for future remedies. But they are very useful pointers along the way. Perhaps at last we have understood the nature of the traffic question and can now begin to seek the answers with a broader base of consensus.

The least spherical distance between two points on the surface of a sphere is that along the minor arc of the great circle on which the two points lie. It is an easy matter to demonstrate this using a cord stretched between two points on a small globe; noting that the circle whose plane coincides with that of the cord contains the centre of the sphere and that it is, therefore, a great circle. It is a little more difficult to prove the fact analytically. The practice of sailing along the shortest route on an ocean passage—sometimes known as ‘orthodromic’ as opposed to rhumbline or ‘loxodromic’ sailing—would require the course to be continually changed (except, of course, in cases in which the rhumb-line and great circle arc coincide). This would clearly be impossible; the term ‘approximate great circle sailing’ is sometimes used to describe the techniques of following a great circle route as closely as practicable.

The International Collision Regulations are explicit only with regard to manoeuvre responsibilities. The manoeuvres themselves have been the subject of a large number of technical papers and conferences, particularly during the past 15 years. Nevertheless, although the use of shipboard radar systems has increased during this time, it is apparent from collision statistics and from the variety of published opinions and recommendations that the manoeuvre-specification problem is not considered as solved. In fact, in many cases, recommended turn manoeuvres can actually lead to a cooperative collision, when more realistic turn dynamics are assumed for the ships. The range of conflicting opinions, few of which are based on an analysis of ship manoeuvre dynamics, provides the motivation for the present study.