Taking the dictionary meaning of society to be the civilized body of mankind – what are the relationships between society and the art or science of navigation? To define navigation itself I have used Wing Commander Anderson's definition of 1961 – ‘Navigation is the business of conducting a craft as it moves about its ways’.

It does indeed give me great pleasure to have been honoured by the request to give this lecture. And it is with a little trepidation that I have chosen my subject, the very title of which could frighten off many people, and I am very glad to see that your Institute consists of people made of sterner stuff. On the other hand, I did feel that the subject in question met the nature of this lecture. It was generally cultural and it relates to navigation. And so let me start on this subject which has a reputation for being difficult. And let me assure you that Einstein's work on relativity is not at all difficult. It is very simple. But it rests on the extremely difficult, abstract theories that we owe to Galileo and to Newton.

The purpose of this paper is to present data and draw conclusions on the chances of collision in different areas of the waters around the UK. The subject of risk analysis has recently grown in importance, and it is often necessary for an operator to demonstrate that a proposed operation is acceptably safe before he will be given permission to begin. Risk estimates are generally of two basic types, backward and forward. Backward estimates are based upon the number of accidents that have occurred in a particular situation, and if there have been many there will be a fair degree of confidence that the risk has been accurately estimated. Forward estimates have to be made where there are so few actual accidents that no backward estimates are possible: they are based upon an analysis of the situation into a sequence of events, the probability of each being known by comparison with data obtained from other situations. Although these data may themselves be reliable, the final risk estimates will depend upon the comparability of the situations and also upon whether the sequence of events has been correctly identified.

A navigation system is not normally changed for social reasons. When changes are made, they are intended to meet new or more stringent requirements, to utilize technological advances, to increase efficiency, to improve safety, or to extend the functions which can be fulfilled. Innovations are evaluated according to their technical feasibility and cost. Not only have social factors failed to influence the nature of changes, but the social implications of changes have also been ignored. Yet greater benefit would often accrue from changes if their social effects were predicted and allowed for. Such predictions are usually feasible.

Social problems in navigation systems are gradually becoming more severe. In the past, man could often compensate for their effects because his role remained sufficiently dominant for him to be innovative and flexible in resolving difficulties, and he retained a full understanding of the system and control over it. More recent aids tend to curtail human communication, restrict the nature of teamwork, and reduce the social aspects of such functions as consultation, supervision, and verification. Man-machine relationships are emphasized, instead of relationships between people. Each man tends to be more remote from his colleagues, and to know less about what they are doing. These effects are generally incidental rather than the reflection of a deliberate policy.

The paper by Captain Cotter on Edward Johnson and the early history of ship's magnetism published in the September Journal sets the scene for the birth, in 1842, of the Compass Department of the Admiralty. Commander Fanning, a former Deputy Director of the Admiralty Compass Observatory, as it later became, here relates its subsequent history. The paper was presented to an Ordinary Meeting of the Institute held in London on 19 December 1979 with Dr J. F. Kemp in the Chair.

This paper traces the fortunes and development of a small department, one of the oldest Admiralty technical departments, from its early struggles with the magnetic compass, through many vicissitudes, economies, defence cuts, wars, intrigues, take-overs and even human frailties. We shall see how technical advances have led to ever more demanding requirements and I hope to show how, by meeting each new challenge, there has emerged the lively, forward-looking organization that today is still responsible for ‘everything that matters’ in navigation equipment, as it was at its inception in 1842.

In areas of high marine traffic density it has been necessary for IMCO to introduce traffic separation schemes to reduce the total number of encounters, and in particular the dangerous head-on encounters. It is now widely acknowledged that separation schemes can and do improve safety. However, as a side effect they unfortunately increase the number of overtaking encounters. For example the introduction of a separation scheme in the Dover Strait (with 1 per cent of ‘through rogues’) has increased threefold the proportion of potential overtaking encounters.

Of all forms of transport, ships are unique when it comes to avoiding one another. Compared with both land vehicles and aircraft they have remarkable freedom of action, so that collisions are avoided less by external regulation than by mariners exercising their individual skill. A framework for their actions is provided by the collision regulations which have evolved over hundreds of years, a process which seems unlikely to reach an end in the near future. Since it is reasonable that any changes should be informed by events, information on what mariners actually do to avoid one another can only contribute to the safety of ships at sea.

This paper is concerned with obtaining information on collision avoidance from radar records. It describes the data extraction and the selection of encounters between vessels, and presents some sample statistical results. Finally, probable applications of the information are discussed.

The Fastnet Race of 1979, over the classic course from Cowes round the Fastnet Rock and back to Plymouth, proved to be the most disastrous in the history of the race, or indeed of ocean racing itself. A storm of exceptional violence, of which the meteorological analysis by itself has provided an inadequate explanation, decimated the fleet causing the loss of 15 lives and the abandonment of many boats. The Royal Ocean Racing Club, which organizes the race, has (with the RYA) issued its own report and the progress of the weather pattern over those fateful days has by now become familiar. In this article Adlard Coles, a highly experienced small-boat seaman (and Institute Gold Medallist), author of Heavy Weather Sailing describes the chaos wrought by the unusually violent and steep seas and attempts to draw conclusions from his own investigation of the affair.

It is of course a truism to note the profound effect that transportation has had on modern society, which is quite simply unimaginable without communications by land, sea and air. The role played by navigational science and its application has of course been somewhat different in each medium. Navigation by air, though, has a special distinguishing feature in that the aviator frequently shares responsibility for the safe and efficient conduct of his flight with another agency, the air traffic control system.

For the foreseeable future, air traffic control will have a major part to play in the navigation and safety of travel by air and so, by implication, future developments in air traffic control will have an influence on society at large.

Turning now from the general to the particular, the author would like to give an example, which may be symptomatic and serve to illustrate the magnitude of the problems that the air transport industry, including air traffic control, may face in the future.

In the first six months of 1979 there were six collisions in the area of the Dover Strait (extending from the Greenwich meridian to 2° 30′ E and from 50° 30′ N to 51° 30′ N) that involved at least one vessel of 500 grt or more. (Two further collisions took place during the next four months.) Collisions have not occurred in these waters at a rate of one a month since 1969. Yet since then there have been several notable changes that should have led to greater safety. The IMCO traffic separation scheme has been made compulsory for ships of all nations through the coming into force of the new Collision Regulations on 15 July 1977. Secondly, the Channel Navigation Information Service was established in England in 1972, and it and its counterpart in France have been monitoring the traffic by radar and making regular broadcasts for more than five years. Finally, traffic discipline has steadily improved, as measured by the number of ‘rogue’ vessels that are held to contravene the routing scheme (Fig. 1).

To decide whether this spate of collisions represents a marked deterioration in navigational standards it is necessary to do rather more than merely count occurrences (Fig. 2). In the first place, any evaluation must take account of the amount of damage to the ships involved and to the environment, and of deaths and injuries to personnel.

The presence of any structure in the sea is a potential hazard to shipping navigating in its vicinity. It is therefore of considerable interest both to mariners and to engineers placing structures such as oil platforms in the sea to try to assess the attendant risk of collision, with such a structure.

We have over a period of time attempted several methods of assessing these risks and it was felt important to link this with our work on marine traffic flows, as experience of the traffic patterns in the southern North Sea was a useful input to the study. Hence we considered an area in the southern North Sea, to the eastwards of the outer Thames Estuary as far as the Middlebank and between the parallels of 51° 08´N and 52° 15´N, since we wished to look at the offshore situation; the area is nowhere less than 3 miles from the coast.

This paper is based mainly on a study carried out in 1976/7 for the UK Department of Industry into the long-term development of air traffic control systems in Europe by a team drawn from the Civil Aviation Authority, the Royal Signals and Radar Establishment and private industry, in which Coopers and Lybrand provided the economic expertise.

Until the early 1970s, air traffic control was almost completely neglected by air transport economists. Economists contributed to the planning of airports and airline operations but not to the third facet of the air transport system. However, in 1970–1, in conjunction with a programme of expansion and improvement of the country's airports and airways, the US Department of Transportation launched a major study of the airport and airways system. This was designed to establish an equitable charging policy between the different categories of user but in the event its recommendations in this area have only recently begun to be followed.

This study consists of an investigation of the point at which ships' masters make decisions to avoid collisions, with regard to the time and distance separation from the other ship. The objective of the study is to find out what factors influence them to make their decisions to manoeuvre at this point rather than at any other; this involves the examination of various factors which could be relevant to the decision-making process, such as the speeds of the two ships, the relative bearing of the other ship, and the length of sea experience of the navigator.

Several computer simulation models for marine traffic systems have been built but various subjective assumptions have had to be made about the criteria on which a decision to make a collision avoidance manoeuvre is based. This study represents the first systematic investigation of the statistical relationships among the factors affecting these criteria.

The benefits to society that would result from the introduction of a given marine traffic management system depend directly on the scale of the system introduced. Since the cost society would be required to pay for a marine traffic management system would also vary directly with its scale, by focusing on the cost of marine accidents both from cargo pollution as well as from loss of life, a direct cost-benefit comparison can be made, indicating the benefit to society attained through a reduction in cargo pollution and loss of life per thousand pounds expenditure on control systems.

Such an analysis implies confidence in the ability to assess in monetary terms the effect of pollution on such non-economic entities as the natural ecosystem as well as the value of such supra-economic items as a human life. In presenting our estimates we not only point out their shortcomings but also admit that past research has been unable to place an economic value on some of the dimensions of the environment, and that therefore any estimates for the social cost of pollution and loss of life should be considered a conservative estimate of the true social cost.

It is only when we have reliable estimates of the social cost of marine accidents that we can proceed to assess the net benefit of a given marine traffic management system. But then further research must be undertaken on the question of just what is the nature of the relationship of controls and social costs.

The memory of the Amoco Cadiz disaster of 1978 is still fresh in the minds of most people. The loaded VLCC drifted on to rocks 3 miles off l'Abervrach and caused almost a quarter of a million tons of crude oil to engulf the Brittany coast. Almost immediately some far-reaching measures were put into effect by the French authorities through IMCO to lessen the likelihood of a similar incident occurring again. Perhaps the most important of these were the fundamental alterations which were made to the traffic separation schemes off Ushant and the Casquets to route the large oil carriers well away from the French coast.

Although its achievement may prove long and difficult, it is surely time to think out the lines along which future traffic systems must inevitably be developed, for we are still largely without any real rationale as to what it is we are to achieve when traffic measures are introduced, whether with IMCO agreement or nationally. We have some of the right answers but have we yet asked the right questions?

Before we can evolve any realistic strategy there must be some consensus across several disciplines; disaster seems to show itself the only effective antidote to fixed ideas. Society is not likely to tolerate this approach indefinitely and a more acceptable mode of progress must begin now, before irrational forces take charge.

The dominant factor has hitherto been safety of navigation, though navigation concerns only the ship and not her cargo, with its contractual obligations and penalties. Yet the risk to society derives almost wholly from the nature of the cargo.

The laws concerning carriage of goods and contracts of affreightment – the province of the ship-operator and his litigation processes – can often be in direct conflict with the statutory requirements of governments relating to navigation and collision, whose theme is safety of life per se and is not concerned with efficiency. It would be reasonable to accept the proposition that the demands of society towards these problems should be solved by traffic-oriented rather than ship-oriented schemes.

This paper outlines the concept of a domain and an evasion area, called an arena, around a ship which are then applied to produce a computer model of ship behaviour. The arena determines when a ship takes avoiding action, as does the land arena which reacts with a discrete series of coastal points to prevent the ship running aground.

The increase in the number and size of ships has resulted in the introduction of traffic routing schemes and the need to understand ship behaviour more thoroughly. The concept of ‘the effective area around a ship which a navigator would like to keep clear with respect to other ships and stationary objects’ has been used by various authors including Goodwin, Fujii and Lewison with varying names such as domain, collision diameters and encounter area. There has been no fixed shape for these areas. Some are circular, others elliptical, while Goodwin's has three segments each with its own portion of a circle. By developing the theory of the domain, it was hoped to be able to produce a model of traffic behaviour which could be used to simulate traffic flows, or specific incidents, in order to study them more fully.

When in 1969 the specific task of scheduling shipping movements in and out of a tide-restricted port had been given as an exercise to a group of harbourmasters attending a symposium at UWIST, Cardiff, the varying methods employed and the apparently large workload involved indicated that a formal study of the problem would produce a more rational solution. The early part of the study, by K. D. Jones with the help of his assistant B. J. Moody, was to develop suitable computer programs to automate a scheduling process such that an ideal pre-movement plan could be arrived at, using as criteria the earliest movement times for given ship-draught and available water-depth.

For a circular contour, which is one of the methods for indicating an error boundary, the author has studied the conditions for the probability of a ship's position (fixed by two position lines) lying within a 95 per cent circle by probability integration. In this case, the coefficient in the equation to indicate the radius is a function of an intersecting angle and an accuracy ratio between two position lines. The author has examined several accuracy ratios and applied the system to the error boundary of a ship's position fixed by three equally accurate position lines. However, as interpolation involves both angle of cut and accuracy ratio, the process is somewhat troublesome.

In this paper it is shown that the accuracy contour for a fix is an ellipse, whether the accuracies of the position lines are the same or not, and a method is developed to replace an error ellipse for two position lines of unequal accuracy with an ellipse formed by two equal-accuracy position lines. The method is extended to three position lines of unequal accuracy. It then becomes possible to indicate an error boundary by a 95 per cent probability circle.

Data relating to a total of 74 tanker casualties in the Baltic area during 1971–5 have been analysed and compared with the earlier collected data on 268 tanker casualties. The discussion concerns local and seasonal distribution. The statistics also cover the nationality, age and size of ship involved. Emphasis is laid upon the need for a more efficient casualty reporting system and new methods of data collection are presented.

The Baltic, Gulf of Bothnia and Gulf of Finland form a limited sea-water basin, where the change of water is small and the evidence of man marked. One of the worst threats to the sea water is the oil leaked from ships. This oil gets into the water in ship casualties or by accidental or deliberate discharge of spill oil into the sea. The oil amounts leaking into the water are very large in ship accidents if the ship or ships in question are tankers in loaded conditions and tanks are damaged.