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.

Captain Scott went to the pole over the Ross Barrier, up the Beardmore Glacier (Fig. 1) which is about 100 miles long, and then on to the south pole, coming out by the same route. The great Norwegian explorer Amundsen went in from the other side over the shelf, up one of the glaciers and on to the pole. Admiral Byrd flew in and out again in 1929. Apart from these expeditions very little has been done in Antarctica and nearly all of it, apart from the fringe, is untouched.

When we started surveying Megalithic sites in Britain we used a cloth tape, but after some years it was realized that it was necessary to be more precise and now we use a steel tape for the important sites. Similarly with astronomy; at first we considered it sufficiently accurate to work to ¼° but now we know that it is advisable to work always to within a minute of arc. This is because we have found out that the erectors of the stones sometimes used distant foresights, either artificial or natural, and by using these they could get an accuracy of better than a minute. The method of observing was for the operator to watch the edge of the celestial body grazing a foresight or running down the edge of a hill. He moved sideways until he got exact coincidence and then marked the position. This first came to our attention when we measured up the site at Ballochroy on the west side of Kintyre.

The purpose of this paper is to look at the nature of the advances being made in inertial navigation and in navigation displays. In avionics as a whole the advance from one generation of equipment to another can take different forms; sometimes, notably in flight control and instrumentation, the potential of new technologies is exploited almost immediately to provide more advanced operational facilities and systems become more complex. Alternatively, as in the application of solid state electronics to produce equipment for general aviation, the technology is exploited to reduce weight, volume and costs. Inertial navigation exhibits both trends but to a comparatively small degree; the basic system requirement is simple to define and has changed very little, one of the reasons being the particularly demanding nature of the technology and the very long development time scales involved.

The collision avoidance of a pair of uniformly moving bodies is considered in three dimensions. The relative motion of the bodies yields an expression relating the time to closest approach, the minimum range, the current range and its rate of change, other variables being unobservable. A Boolean relation is then proposed that is satisfied whenever the minimum range and time to closest approach simultaneously fall below given thresholds. The relation is further studied, in particular with regard to the issue of false and premature alarms. An airborne collision avoidance system is a possible application.

Anthropologists tell us that over 500000000 years ago the seas swarmed with some type of marine life and that during the Devonian period of 350 0000 000 years ago we could find the first species of monk fish that is now in high demand on the fish market place and sought after in strange hostile waters by European fishermen. The sharks were introduced to the planet at about this time and until this day have had the reputation of being the ocean's most voracious predators.

This paper was presented at a seminar entitled a European Concerted Approach to Vessel Traffic Services for Safe Navigation – EEC Project COST-301, sponsored jointly by the Institute's Netherlands branch and the Royal Institute of Engineers, Delft University of Technology and the Netherlands Directorate General for Shipping and Maritime Affairs held in Delft on 20 January 1986. It was published under the auspices of the European Environmental Bureau, an independent coalition body of leading environmental organizations in all the European Economic Community countries (with a total membership of over 10 million). The paper, of which the following is a condensed version, seeks to comment on the implications for environmental protection of the various COST-301 research programmes, and to assess the contribution which the findings resulting from them may make to future European coastal state policy and international measures.

Aline De Bièvre is with the European Environmental Bureau and John Kemp is Professor Emeritus at the City of London Polytechnic.

In the next decade there will be an increasing demand for more accurate self-contained navigation systems due to more stringent air traffic control requirements, particularly with the introduction of the supersonic transport. Although inertial systems have been fairly widely used in military aircraft and missiles, the only self-contained systems in service in civil aircraft are dead reckoning systems based on measuring the aircraft's velocity and heading and drift angle. A big improvement has been effected in the measurement of velocity and drift angle by the introduction of doppler radar. The accuracy achievable with doppler is not matched by the accuracy of existing heading reference systems and the overall accuracy is, at present, inadequate for future requirements.

An inertial navigation system is a possible alternative but its cost will be two to three times that of a doppler heading reference system.

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 title, the gift of Frank George, derives from The Troublesome Voyage of Captain Edward Fenton, E. G. R. Taylor's masterly edition of narratives relating to one of the less successful of Elizabethan adventures. Fenton's voyage of 1582, to China and Cathay, was a total failure. But the tale endures.

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 presented to an Ordinary Meeting of the Institute held in London on 22 November 1978, Captain Woodfield, who was for nineteen years master of Royal Research Ships in support of British Antarctic Survey operations, discusses some of the problems of navigating in this ill-charted and ice-ridden area. The presentation was made jointly with Lieutenant Commander P. Le Pla, formerly Navigating Officer of the Ice Patrol Ship HMS Protector whose paper on Antarctic navigation was published in Vol. 31 of the Journal. The President was in the chair.

From a weather forecasting viewpoint the situation of the sailing yacht at sea is unique. The yacht is small and entirely dependent on one meteorological element, wind, for its motive power. It is a device where an increase in that power increases the safety factor of speed by a very small margin while at the same time it increases the danger factor to a much larger degree. This is mainly because the increase in wind speed is accompanied by wave building and the latter increases with wind speed, time and, very dangerously, with approach to the shallow water that must often be traversed before safety is gained. It is not only wind speed that puts yachts in danger, but the combination of wind speed and attendant seaway. However seaway is not an element predicted in weather forecasts; it is a branch of seamanship left entirely to the skipper on the spot.

Although meteorology probably has a greater influence on marine and air navigation than any other individual science, many users are not fully aware of the problems of present-day forecasting, nor do they make full use of the services available. This paper is intended to give some idea of the value of observers' reports, the importance of communications, and the problems of present-day forecasting. In particular, attention is drawn to the rapid increase in upper air soundings and the interdependence of surface and upper air observations in predicting the elements for all marine and aeronautical services. Arising from the application of upper air data to surface forecasting, the paper emphasizes the value of applying comprehensive analyses and of marine forecasts prepared by weather centrals ashore; in areas where facilities are not available to the marine user, however, knowledge and experience of single-observer forecasting are still needed.

H.M.S. Challenger is one of Her Majesty's surveying vessels. She is a ship of 1140 tons and carries a complement of 96 officers and men. Built in 1931, she is named after her illustrious predecessor in which the wellknown world oceanographic cruise was made in the years 1872–6. This expedition brought back a great wealth of chemical and physical data, and a huge collection of plants and animals from the oceans. These were checked and analysed and eventually, under the guidance of Sir John Murray, who had been a scientist on board, the results were published in fifty folio volumes known as the Challenger Reports. These reports still form, the starting point for the study of the oceans and marine life.

Orientation within orienteering is dependent on the use of two basic strategies; that is, either a compass or Magnetic-North-based strategy, which relies on the use of one set of information; or the use of a map and landmark-based strategy which relies on the use of at least two sets of information. Walsh and found that, when given the choice, young children use the compass-based strategy when following complex potentially disorientating routes.

The efficacy of these two basic orientation strategies was investigated within three different orienteering environments: (1) a familiar known environment; (2) a familiar unknown environment and (3) an unfamiliar unknown environment.

Subjects, age range from 9 to 10·5 years, completed an appropriate orienteering route in each of the environments. Individual mini-cassette recorders and tie-pin microphones were used to record data using a ‘think aloud’ technique as subjects followed their selected routes. Transcripts of the taped data produced a total number of uttered statements for each subject within each environment. A qualitative analysis of these statements identified the following groups of statements expressed as percentages of the total number of statements (as reported by Thorndyke and Stasz): (a) Orientation statements; (b) Relocation or error correction statements; (c) Statements about distractions; (d) Self-efficacy statements.

There was a higher reported use of the compass-based strategy for orientation within the familiar known environment which supported the earlier findings of Walsh and Martland. Although the percentage of compass-based orientation statements was smaller in the familiar unknown and the unfamiliar unknown environments, there was a pattern in the use of orientation strategies within these two environments. Typically, the compass-based orientation strategy was used for initial orientation at the beginning of the route and at the pre-defined control points along the route, whilst the landmark and map-based strategy was used as a means of maintaining and reinforcing orientation within the route. Relocation statements typically reported an awareness of disorientation and were generally followed by attempts to reorientate. Whilst none of the subjects used relocation statements within the familiar known environment, relocation statements were used within the familiar unknown and the unfamiliar unknown environments.

This evidence suggests that both orientation strategies are used in orienteering routes, but that each strategy is used selectively depending on the environment. These findings clearly have implications for the sport of orienteering – particularly the introduction of basic skills to young performers. They support the argument that is essential to introduce the map and compass simultaneously and that relocation and orientation skills should be coached concurrently.

Although the merchant navy is one of the earliest users of navigation, it is today by no means the most spectacular user, especially in comparison with present-day hovercraft and the coming supersonic civil aircraft. This absence of the spectacular is, however, not due to lack of imagination or progressiveness, but stems from very natural circumstances. These circumstances are the relatively low-if not the lowest-transportation speed, the application of the laws of Archimedes to obtain the required carrying capacity, and the laws of economics which dictate a delicate balance between investments and net revenue.

This paper discusses the necessity and feasibility of the application of Pulse Doppler Radar in vts through analysing the limitations of the non-coherent, single frequency, radar and the advantages of PD radar.