Over the past thirty years progress in the technologies associated with navigation has been so rapid as to produce a change in the balance between the art of the navigator and the practice of the technologist. The Royal Institute of Navigation was founded at the beginning of this era and one of its major aims was to provide a forum for discussions between practising navigators, scientists and engineers. Therefore, it seems that a consideration of the technical changes should help the Institute to adapt, much as all our social institutions are adapting, as a result of wider changes brought about by science and technology.

Presented at a meeting of the Solent Branch of the Institute held, by courtesy of the Director, at the College of Nautical Studies, Warsash, on 21 September 1978.

Put your trust in God and the Admiralty Chart! Every one of nearly four million charts issued each year by the Hydrographic Department is as up to date as possible on the day on which it leaves our premises; nevertheless we are increasingly conscious that far too many of the charts are no longer adequate for the uses to which they are now being put.

Numerous collisions over the years have emphasized the need for rapid and efficient ship-to-ship voice communication systems. Such systems, set up to satisfy the demand for more and better channels through which messages can be sent, should guarantee that both sender and receiver come to share the same thoughts and feelings. ‘It can be said that two expressions have the same meaning if their utterance results in the same change of behaviour.’ Recognizing that voice communication systems cannot be effective until all parties speak and understand the same ‘language’, the Maritime Safety Committee of IMCO has developed the Standard Marine Navigational Vocabulary, a significant landmark in the attempt to achieve the maximum safety to navigation and the most appropriate conduct of ships at sea. This paper will concentrate on the objectives of the Vocabulary and will try to ascertain if such objectives have been achieved. The analysis will emphasize the viewpoint of ‘non-English speaking people’ using English ‘for the interchange of intelligence between individuals of all maritime nations’, and will take linguistic considerations into account.

In recent years a great deal of research has been carried out in the twin fields of ship and aircraft navigational systems. The areas investigated have been closely related, but since 1945 the work has always been conducted independently, with virtually no cross-reference between the two industries. During the war years, however, this was not so and intensive research at that time resulted in some remarkable technical advances which related to both fields. The aids to navigation which then emerged have remained until recently absolutely fundamental and in marine navigation they have formed a platform of reliability, particularly the Decca Navigator system and radar. In aviation, airline competition on the transatlantic routes and the need for absolute safety has maintained a continuing process of evolution in the design of navigation and control systems. One such aid to emerge has been DME and, with the research and development complete, this is now a standard device for both military and civil operators throughout the world. A chain of ground beacons has been set up to cover the major world air routes and there are a considerable number of these beacons in the United Kingdom.

In this paper Dr Y. Iijima of the Tokyo University of Mercantile Marine and Professor K. Honda of the Kobe University of Mercantile Marine examine the hydrodynamic and navigational factors that determine the safe width of a channel for vessels of a given size and performance characteristics. The results are compared with the widths of existing channels in Japan and elsewhere.

Modern ship control and navigation systems involve a complex variety of intricately interwoven electronic, electrical, mechanical and hydraulic devices. It has become appropriate therefore to devise a convenient method for representing mathematically the dynamic characteristics of these systems and the elements which comprise them, so that block-diagram modelling can be implemented. This is ideal for displaying the interrelationships of such systems pictorially and has the added advantage of simplicity and of indicating realistically the actual processes which are taking place, as the models refer to the relationship between mathematics and the real world.

In this paper, which was presented at an Ordinary Meeting of the Institute held in London on 13 December 1978, Dr Corlett, of Burness, Corlett and Partners, describes some of the effects that hydrodynamic interaction has on shiphandling and safe navigation. He concludes that the whole subject of interaction should nowadays be taught to mariners as part of their normal instruction.

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.

In this paper, which was presented at a symposium on electronic aids to air navigation held in Paris in November 1977 (and subsequently published in the Journal of the French Institute of Navigation), the authors first analyse in detail the mental processes of an aircraft pilot and the ergonomic factors that should underlie the design of any flight data display. They then describe a cathode-ray tube display designed for use in civil transport aircraft and the modifications they found desirable in the light of simulator trials.

The Department of Trade has recently issued a Merchant Shipping Notice (No. 845) entitled ‘Dangers in the Use of VHF Radios in Collision Avoidance’. Though they recognize that ‘the practice of using VHF radio as a collision avoidance aid may be resorted to on occasion, especially in pilotage waters’, the tenor of the Notice seems clearly designed to inhibit the use of this valuable aid to navigation. Their attention seems mainly absorbed by the undoubted dangers attending its haphazard use, which appears to be the salient feature of most of the ‘official’ attention directed towards the use of this device.

The anonymous author of a paper published in the November 1857 issue of The Nautical Magazine, introduced a novel philosophy in relation to the location of lighthouses. At the same time he discussed the proposition for a coastal traffic separation scheme for the English Channel — notorious then, as it still is, for its high incidence of collisions and groundings. The proposal was made just two years after Walter R. Jones of New York made his suggestion to Lieut. M. F. Maury of the United States Navy for an ocean traffic separation scheme which materialized in the form of Maury's ‘steam lanes’ for the North Atlantic.

A recent study by digital computer simulation modelling of traffic interactions in the Dover Strait by Batkin made use of a so-called ‘decision-distance’ criterion for locating the point at which a crossing manoeuvre was to begin. This decision-distance was measured along the course of the vessel involved. The manoeuvring vessel was regarded as making an abrupt change of course, by an angle β to starboard on reaching the decision-distance, it having been ascertained beforehand that, in the absence of a manoeuvre, the vessel having the right of way would infringe the other's domain. Although it seems unlikely that such a simple procedure is used by mariners in practice, it seemed useful to examine the implications of the method in terms of the angles of manoeuvre involved, and to make a comparison with an alternative procedure involving the range between ships.

The distribution pattern of navigational errors is inherently an important subject bearing as it does on matters of navigational safety. The work of Hiraiwa on the basic distribution of Omega observations is thus a most welcome addition to the literature. There is, however, a major limitation in the data base used by Hiraiwa which could lead to serious errors in analysis of safety based on his findings.