The problem of collision avoidance at sea would be an important one even if accidents were rare, but the evidence suggests that they are much more common than one might expect. In the eight years leading up to May 1963 there were 60 collisions in the English Channel area and in the following eight years the number increased to 94. With the development of navigational aids such as radar one might have hoped for a decrease. The suggestion that the increase is quite likely attributable to the possession of radar is ironic indeed. It would appear that having the use of this ‘safety’ equipment allows the mariner to take greater risks, but that the risks which are in fact taken are greater than the equipment allows. We would do better to go back to fog horns alone. Even if over-confidence is not the only factor responsible for the increase in accidents, it does, nevertheless, illustrate the importance of the psychological variable in any man–machine system.

Collisions at sea, however, are not simply due to errors in a man–machine system, It is, of course, the hardware that actually collides, but the cause of the interaction lies in the decisions and indecisions of the two human agents controlling the vessels. It is essentially a social encounter. It is for this reason that the work initiated by Captain Kemp is greatly to be welcomed.

On the night of 2 September 1974 Morning Cloud, a 45-ft. ocean racer belonging to the Rt. Hon. Edward Heath, was sunk in a severe south-westerly gale off the south coast of England. The boat was on passage from the east coast to the Solent with an amateur crew for the passage, two members of which lost their lives. Here K. Adlard Coles, a Gold Medallist of the Institute and author of the classic work Heavy Weather Sailing, describes the circumstances in which the disaster occurred as told to him by Don Blewett, who was skippering the boat at the time. Don Blewett's own account appears in Seahorse (Jan./Feb. 1975) the magazine of the Royal Ocean Racing Club.

Perhaps the main concern of the Master today should be to foresee the future and adapt himself to it, but that is true for everybody. The gradual change in his position is apparent. Sixty years ago sailing announcements always mentioned the ship's name and her Master's name together, they formed an inseparable unit; today we may look in vain for the Master's name in such announcements. Such outward signs merely illustrate a gradual decline in the Master's position within the overall shipping company hierarchy, though not in the hierarchy on board. It is the result of totally new involvements of shipping management as our society in general becomes more complex and interdependent.

A Device known as the Simplified Astro Platten (S.A.P.) is presently being marketed by the Bucks. Gear and Engineering Co. Ltd., of Middle Lane, Mount Pleasant, Aylesbury. It consists of a large rectangular plastic sheet some 29 in. by 16 in. on which are engraved two graduated semicircles with parallel diameters separated by a space of 2 inches. This sheet, on which pencil lines may be drawn and which can easily be cleaned when the lines are no longer required, is housed in a stiff plastic protective envelope. A mimeographed booklet of instructions includes examples and answers, for practice. There is no indication of the principles on which the device is based but the idea is certainly not new.

In 1974 Dr. David Lewis was awarded the Institute's Gold Medal for his work on indigenous navigation methods in the Pacific, and his many remarkable feats of practical navigation. The following account is of perhaps the most remarkable of his voyages which was an attempt to circumnavigate the Antarctic Continent on his own. The first part of the voyage, which culminated in January 1973, was mentioned in the formal citation for the award; the second part, which is every bit as remarkable, finished in Capetown in March 1974.

No one had ever sailed single-handed through the Southern Ocean to any part of the Antarctic continent, not even by way of Drake Passage from Tierra del Fuego, which involves a crossing of only about 400 miles of open sea. Since the sole practicable Antarctic landfall for a small vessel is the Antarctic Peninsula (formerly Graham Land) below Cape Horn, Australia, some 6000 miles to the west, was a far from ideal starting point. However, this was where I was working so that there was no alternative but to make Sydney the point of departure.

In the western North Pacific and the South China Sea the typhoon is one of the most fearsome elements a ship can encounter and one of the major decisions that must often be considered is whether to seek, or remain in, the shelter of a harbour or to take evasive action and ride out the storm at sea. With the many variables involved, such as topography, the different directions of approach of tropical cyclones, type of holding ground, size and shape of the ship, &c, it is often not possible to stamp a particular harbour as safe or unsafe. This paper deals with some of the many factors that a Master should consider when deciding to remain in, or sail from, Hong Kong on the approach of a typhoon.

This paper describes the historical background to the Göttingen Professor Tobias Mayer's bid under the terms of the Act 12 Queen Anne, cap. XX (1714) to obtain a reward for having constructed lunar tables of unprecedented accuracy (to about ± ½′) which promised to make both useful and practicable the lunar-distance method of finding longitude at sea. Parliament's decision in 1765 to award £3000 to Mayer's heirs marked the end of an eleven-year period of lively correspondence conducted on the latter's behalf between Professor Johann David Michaelis, Secretary of Hanoverian Affairs in Göttingen, and William Philip Best, one of George III's Privy Secretaries in London. The Nautical Almanac came into existence as a direct consequence of the success of these diplomatic negotiations.

This study of fifteenth-century Arab sailing directions for the Indian Ocean is translated from a paper which was published in the July 1974 issue of Navigation, the Journal of the French Institute of Navigation. The spelling of modern place names has been assimilated to that of the Admiralty Charts and Sailing Directions but other Arabic names and terms have been left in the authors' approximate transliteration. Quotations from the Arabic texts are printed in italics.

As one of many disciplines which involve the study of bodies and their motion, the science of navigation is heavily indebted to Sir Isaac Newton (1642–1727). Newton's outstanding contribution to science was his conception of the abstract idea of force and its mathematical formulation. This enabled the development of quantitative mechanics through the application of, for example, his Law of Inertia and his Law of Universal Gravitation. Whilst limitations in Newtonian physics have now been exposed at the level of sub-atomic particles moving close to the speed of light (Einsteinian physics), Newton's Laws remain the foundation stone to the solution of most everyday dynamical problems.

Evidence exists which demonstrates that primitive attempts to employ astronomical principles for the purposes of navigation were made by Mediterranean seamen at least a thousand years before the beginning of the Christian Era. But the significant development of nautical astronomy as a science came about at the time when the Atlantic Ocean was being opened up by maritime explorers during the Golden Age of Discoveries, and the lead at the time was taken by the Portuguese under the sponsorship of Prince Henry the Navigator.

A ship domain may be thought of as the sea around his ship which the navigator would like to keep free, with respect to other ships and fixed objects. In this paper, which was read at an Institute meeting in London on 12 February 1975 with Captain R. Mayboum in the Chair, Mrs. Goodwin describes studies to determine the dimensions of a domain based on radar simulator performance and traffic surveys in the North Sea. She also suggests applications of this domain concept to marine traffic engineering problems and to traffic control schemes.

In recent years there has been an increasing interest in the sea for it is to the world a means of communication, a source of food and a source of minerals.

Professor Cortesão sent the following message to the Annual General Meeting of the Institute on 23 October which he had been unable to attend to receive personally his Honorary Membership. An account of the meeting appears at page 111.

The Honorary Membership which the Royal Institute of Navigation bestows upon me, when I have reached the eighty-fourth year of my laborious life, the last forty years of which have been largely dedicated to the study of the history of early cartography and navigation, impresses me deeply and I am very sorry that, due only to my advanced age, I cannot be present at this ceremony to thank you personally for such a great distinction.

The writer's previous article on this subject endeavoured to show that two differing plotting philosophies were currently being offered, one in which the predicted future positions of targets were correlated in time, and the other which displayed unrelated areas in which own ship could come into close quarters with target vessels.

The practical navigator relies on his ability to perform two fundamentally distinct operations: fixing his position and determining the course to steer. Guidance, in the sense that he receives (or generates within his craft) signals which continually define a vector coincident with his desired track, is not normally available to him.

Certain radio aids, notably the hyperbolic navigation systems, have however, frequently been used in the guidance role where the direction in which the signals can be particularly easily interpreted happens to coincide with the course to be steered. Thus, flying down a Decca lane is an acceptable operational technique which corresponds to making the aircraft follow the locus of constant range-difference to two points at known locations. It is not in principle necessary for the craft to perform the conversion from hyperbolic to Earth coordinates in order to do this.

It can be said of the oldest form of radio position-fixing for ships and aircraft, by direction finding, that two or more position lines in the form of the bearings of known radio stations provide a ‘common-reference’ fix: within the accuracy limits of the technique, all craft visiting a given spot will get the same bearings, and hence the same fix, at that spot. Similarly, the modern hyperbolic systems Decca, Loran and Omega each provide, within their respective accuracy limits, a common frame of navigational reference for all users. As the term implies, the users can fix position at will within this frame of reference without first having to undertake a calibration or similar procedure at some accurately known position.

I am indebted to Captain Duncan M. Henderson (Journal27, 536) for causing me to seek further than I had done previously to enable me to prove that ‘F’ in old log-books stood for fathoms and not fractions.

I would quote the following authorities who all state definitely that the ‘F’ meant fathoms and that there were usually eight fathoms to a knot, at any rate in the eighteenth and early nineteenth centuries. They are:

The remarks of Mr. Harrison under the above title demand some further comment. One can certainly agree with his substitution of ‘prediction’ for ‘plotting’ but not with his deletion of ‘supposed’. The latter begs the whole question whether the operator will be dangerously deceived and this is far from proven. The latter part of his second paragraph is a generality; there will be many combinations of range and speed in which the result will not be satisfactory.

Mr. Harrison implies, although he does not come right out and say so, that errors arising during ‘classical’ manual plotting are ‘operationally’ acceptable while the errors in automatic plotting are unacceptable. Such a conclusion is illogical if one is willing to concede that any manual plotting procedure can be automated by the use of a digital computer. To examine this assertion in greater detail one may consider the automatic plotter to be made up of a data extraction section and a data processing section.

The use of hand-held pocket calculators for navigation was discussed at an open meeting of the Technical Committee held in London on 7 May 1975 with the President; G. E. Beck, in the Chair. A number of those who took part in the discussion have prepared written contributions which are printed below with the account of the meeting.

W. D. Rushworth (Directorate of Overseas Surveys, Ministry of Overseas Development): Land surveyors, unlike navigators, do not have to do instant calculations but before we leave an area we have to carry out sufficient computations to ensure there are no blunders in the observations. Overseas in developing countries this usually means a computing session in camp every evening and until a couple of years ago this was a ponderous business, using hand cranked calculators and massive books of eight figure trig. tables. For the surveyor moving on foot these items were often a real burden so that the advent of battery-operated electronic calculators was a godsend, especially once we got calculators with pushbutton trig. functions.

It is becoming common for ship's officers and pilots to attend special simulator courses to learn the handling of new ships or the navigation of particular channels. A simulator can be defined as any likeness of an object or objects, thus a simple drawing of a ship's bridge is a form of simulation, as is a function diagram or a small-scale model; full-scale models or ‘mock-ups’ are more advanced types of simulator. However a simulator is more commonly taken to be a more complicated set of full-scale models in combination with small-scale models, which usually have the ability to respond to different manœuvring actions with changes in the instruments or the surroundings.