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.

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.

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.

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.

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.

The accelerated growth of aircraft operations is causing severe congestion problems at major airports throughout the world and adding heavy burdens on Air Traffic Control which result in traffic delays. Area navigation is regarded as a solution to this problem and a means of more efficient and safe utilization of airspace, both en route and in the terminal area. It is important to evaluate the navigation accuracy of RNAV systems in the Japanese airspace before introducing the concept of Area Navigation technique.

Among the many problems arising from the exploitation of North Sea oil is that of finding practicable landfalls for the proposed pipelines. The oil companies have been confronted with some of the most difficult landfalls yet experienced where the requirement for precise positioning has been paramount. This paper, which was presented at a meeting of the Institute held at the Southampton School of Navigation on 23 October 1975, outlines the problems encountered and the methods used to overcome them.

Dr. Freiesleben, an Honorary Member of this Institute, discusses the geometry of ellipses and hyperbolae on the sphere. These are the curves which correspond to position lines based on the constant sum or difference of distances from two fixed points. Originally applied to astronomical position lines they now have a wider application to electronic fixing systems of global coverage like Omega.

It is natural that present attitudes towards safety at sea and collision avoidance should reflect a justifiable preoccupation with electronics in meeting the exigencies of marine traffic congestion and collision hazards. Despite the frequency with which marine casualties occur during darkness and in conditions of poor visibility there is a tendency to minimize the positive, if modest, contribution of efficient and distinctive ships' navigation lights towards safety at sea in these circumstances.

In a recent paper in this Journal the Director of the Royal Institute of Navigation describes some methods of navigating small vessels; he rightly includes classical astronomical navigation and describes some speedy and well-known methods of solution. In spite of the availability of such tables and mechanical devices the solution is not within everybody's reach because nautical ephemerides are always necessary; convenient tables are the Sight Redaction Tables for Air Navigation (A.P. 3270) from which the elements for tracing out the lines of position through the intercept method can easily be extracted. The simpler tables here proposed present the following advantages:

(i) the ephemeris is not required

(ii) the observed sextant altitude need not be corrected for refraction and dip.

The idea of an ‘Altitude-Azimuth’ almanac is not new though most effort (see this Journal, Vol. 1, 185, 1948; Vol. 2, 285, 1949) has been concerned with the Sun and planets rather than the stars. For the stars the simple problem is that observations are recorded in mean time (say G.M.T.) whereas the positions of the stars depend on sidereal time (L.H.A. Aries) given by: L.H.A. Aries = G.H.A. Aries + west longitude. A full account of star tables (and diagrams) using a mean-time argument (and thus avoiding using the Almanac to give G.H.A. Aries) is given in ‘The Genesis of the E. A.N.T.s’ (this Journal, Vol. 6, 333, 1953).

The use of the traverse table for plotting a bearing from an object outside the coverage area of the chart, as described by Pesi Sorab, suggests a graphical solution that might be preferred by some navigators. The method is analogous to advancing a position line by advancing the position of the object observed.

Well developed states have aircraft following airways in an orderly fashion under full positive A.T.C. control with good v.h.f. communications. The least developed states on the other hand are overflown by aircraft each on its own desired track with little if any control or communications. Many emergent states have taken the simplest step on the road to civilization in the air; they have specified mandatory airways or routes. In the most primitive situation aircraft, usually few in number, are protected against the risk of collision by natural dispersion. In other words the sky is so big and aircraft are so small that, provided they are spread out, there is very little risk of collision. The broadcasting of position reports by aircraft by v.h.f. on 126·9 m enables pilots to resolve any potential encounters that may occur. This situation occurs over the western Sahara.