The main reason for improving the navigation of merchant ships today is economic, determined by factors such as the price of long-shoring and the penalties for late (or early) arrival in port. In this paper, which was presented at an Institute meeting on 13 April 1962, the Assistant Marine Superintendent of the Holland–America Line examines critically the standards of equipment and operation in modern cargo vessels and suggests a whole range of improvements based on experience within his own Company.

Four steps to Longitude! If we chose, we might interpret the phrase by a sequence of four names: Ptolemy, Charles II, Tobias Mayer and Nevil Maskelyne—the last in 1763. But in fact the steps represent the four marine timepieces made by John Harrison—familiarly known as H1, H2, H3 and H4 of which the last proved its efficacy in 1762. The longitude was found, and by a ‘machine’, just two centuries ago. Now the bi-centenary is being celebrated by a very elegant and informative exhibition at the National Maritime Museum, Greenwich. No navigator should miss it. Even if he thinks scorn of ‘ancient history’ he owes the inventor of the first English chronometer a tribute of respect.

Training courses on marine radar simulators are held in this country at the Navigation Schools and Colleges in London, South Shields, Hull, Glasgow, Liverpool and Cardiff, with Southampton starting at some future date. The entry for each five-day course is limited to six members and places on the courses are at present generally restricted to serving masters and chief officers. The purpose of these courses is to give seagoing masters and senior officers realistic practice in manœuvring their vessels by radar in conditions of bad visibility without any of the risk involved in an actual encounter between vessels at sea, as well as risk-free opportunity to try out and test the different methods of radar presentation and plotting.

Even as recently as 1954, although informed opinion ashore was otherwise, at sea, and here one can only broadly generalize, the principles of plotting were neither universally accepted nor practised, and it may be that this was due largely to the fact that there still remained disagreement as to the practicability of plotting. Indeed, even now, there must be a limit on the number of targets that can conveniently be manually plotted.

The Safety of Life at Sea Convention, 1960 amended the Collision Regulations to take cognizance of radar, and to give guidance on the use of radar in fog. The Admiralty Court has indicated that if a vessel is fitted with radar she is obliged to use it and, even more important, that there is an obligation upon the observer to use the radar properly. The phrase ‘using the radar properly’ has in Case Law been judged to necessitate some form of plotting, and it is of passing interest to note that the vast majority of collisions involving vessels fitted with radar can be attributed to immoderate speed, or a failure to appreciate the information provided by the PPI.

The use of VLF radio transmissions as the basis of a navigation system has been under consideration for many years, and has been the subject of extensive theoretical work and field trials. Although a system of this kind has yet to reach operational status, the subject is of considerable interest in relation to marine and to air navigation. This paper indicates the main features that might be expected to characterize a practical VLF navigational aid, and outlines some of the work that has been carried out in this field. Brief reference is made to the question, so far largely unresolved, of the operational scope for VLF systems.

This paper, having first reviewed briefly the operational characteristics of present radar displays, deals with a new technique for presenting the radar data whereby a large, bright, high-contrast radar picture can be produced on a flat plotting surface by projecting in sequence rapidly processed photographs of a PPI cathode-ray tube presentation. It is followed by an account, by the radar officer in S.S. Canberra, Mr. D. W. Sims, of the use of the system at sea.

The first shipboard installation of the Kelvin & Hughes rapid processing photographic radar system has now completed 500 hours service aboard the P. & O. liner Canberra and the navigational and technical staff in the ship have had a reasonable opportunity to evaluate the equipment from all practical aspects. The advantages of this type of display are, in summary:

(1) A full size plotting screen (in this case 24-in. diameter) is available for direct plotting.

(2) All operations may be carried out in broad daylight without the necessity of having to accustom the eyes to a dimmed PPI.

(3) There is no radar hypnosis. Information is presented as a solid, steady picture at the end of each cycle.

(4) A permanent record of the radar information is immediately available for playback at any later date.

(5) Several officers may view the screen at the one time and discuss the plot while it continues uninterrupted. This is a very favourable point in a large vessel of high speed where three or more senior officers may wish to know at all times exactly what is happening on the radar plot.

(6) By using a processing/exposure cycle of seven seconds or more, a build-up of picture strength, true track of vessels, &c. is possible.

In recent years there have been a number of accidents caused by aircraft flying into high ground. The aircraft were mostly on nonscheduled rather than scheduled flights. This has resulted in much publicity being given to such questions as the licensing of the operators, the sufficiency of the radio or radar carried, and the route-experience of the pilots. These questions are of course relevant, but there is one further question which ought to be investigated and which has received little attention: it is the adequacy or otherwise of the means employed to show relief on charts.

Under present policy the only picture of the relief is on topographical maps (Fig. 1), but it is on charts (Fig. 2) that the route and aids are shown. If the pilot is to check his safety-height in the air, he can do so only by coordinating the maps with the charts. This is cumbersome when he is pressed for time, and generally he does not do it; he flies on the charts using flight altitudes that have been pre-calculated, and the maps remain in the navigation bag unused.

The following report, here printed in a slightly abridged form, was prepared under a contract with the U.S. Office of Naval Research and covers the results of research at Key West, Florida, and near Newport, Rhode Island, as well as afloat during the period January 1958 to May 1961. It has so far been unpublished. It describes the results of investigations into the use of high-magnification sextant telescopes and makes recommendations for the improvement of marine sextants and their use. It is here published with a prefatory note and final general comment by Mr. D. H. Sadler, Superintendent of H.M. Nautical Almanac Office.

In the January number of the Journal (15, 104) Captain Wylie discussed the apparent conflict which existed between certain mariners and certain mathematicians about the efficacy of the Collision Regulations at sea. His contribution, which followed the publication in the October 1961 number (14, 379) of Mr. Calvert's ‘Comparison of Two Systems for Avoiding Collision’, was discussed in the same number by a selection of seamen and mathematicians. Followers of this controversy will be interested to read the remarks of Captain Weekes, printed on p. 271 on the subject of how imperfectly many ships' officers understand relative movement. Commander Clissold's suggestion, printed in the same discussion, that Calvert's and Hollingdale's rules should be tested on marine radar simulators is also to the point.

Captain Wylie begins his paper by evoking a philosophic vision: a planet full of colliding ships, all staffed by mathematicians. He concludes by rejecting, on behalf of mariners, the help of the mathematicians. The maritime record also evokes a vision: the colliding ships are somewhat fewer, but the main difference is that every one is staffed by persons other than mathematicians. The latter vision rather implies a need for help from somewhere.

As Mr. Sadler points out, there can be no conflict between mathematicians and navigators, provided the mathematicians have adequately fulfilled their job. If, however, the navigators fail to follow the mathematics, or even to check the results by taking a few examples, then there will be plenty of misunderstandings; to bring ‘philosophy’ into the discussion is to return to the attitudes of the Middle Ages, and to obscure technical issues which are perfectly clear and simple.

Passenger and cargo liners sailing on regular routes follow tracks for a given voyage, taking account of the various seasonal conditions which may apply, and masters of these ships, with many years experience in a particular trade, can decide without great difficulty the most advantageous track for their ship when planning a voyage for a given time of year.

In the transport of oil, on the other hand, it is not common to employ ships on regular voyages, and the great majority of tankers are employed in world-wide trading, so that although a particular oil company may have a number of ships constantly voyaging on a particular route, a high degree of flexibility is maintained and ships are regularly changed from one route to another. This means that the tanker master is called upon to consider the requirements for optimum routing of his ship on any ocean voyage. Further, he is often given his orders with fairly short notice and, in some cases, he may have his destination changed either at the last moment or during the voyage, leaving him little time to consider the many factors which have to be taken into account when planning the best route for the voyage to be undertaken.

‘The mark of a good navigator is not so much his ability to obtain accurate information as his ability to evaluate and interpret correctly the information available to him.’ So writes Captain Alton B. Moody, U.S.N.R. in the course of an interesting correspondence in the February number of the U.S. Naval Institute Proceedings. In the August 1961 number (page 132) Captain Robert Lee Rhoads, Jr., a shipmaster, suggests that the ‘cartwheel’ set of astro-sights, where four position-lines intersect each other at angles of about 45°, is inferior to the square where the position-lines intersect at approximately 90°, which gives a more reliable fix. One of Captain Rhoads's illustrations shows a case of a 4-minute systematic error in a ‘cartwheel’ fix giving a position 6 miles in error, where the same error would have had no effect on the position interpolated from four sights taken at 90° to each other.