Many of the tasks which have occupied the navigator ever since measurement and calculation were first applied to the subject are now being carried out or aided by technical devices. This has been going on for a long time, and I would like to consider how far we have got, and what will remain for the concern and interest of our Institute when this technical growth has fully matured.

Arising from my recent note on short-method nautical astronomical tables, Dr. G. D. Raasveldt of The Netherlands has commented on an elegant solution to the general nautical astronomical problem developed in 1884 by Captain (later Commandant) Emile Guyou of the French Navy. Guyou's method is, indeed, ingenious: it affords an extremely brief solution to the problems of computing hour angle and azimuth given the three sides of the astronomical or PZX triangle. Moreover, by its principles all problems in nautical astronomy may be solved by means of one single-entry table. Sines and cosines, tangents and cotangents, secants and cosecants, versines and haversines—natural and logarithmic—are all made redundant for this purpose by a table whose function is, in general, limited to mercator sailing. This is the common ‘Meridional Parts Table for the Sphere’.

How do Aborigines find their way across the arid wastes of Central Australia? Certainly their feats of practical orientation and tracking are legendary. Are their methods in any way analogous to the non-instrumental arts still surviving in parts of the insular Pacific? (Lewis, 1972). In 1972 the professor of Pacific History at the Australian National University generously extended to Central Australia the accepted bounds of Oceania, to allow me to travel the Simpson Desert with Antikarinya tracker Wintinna Mick in an attempt to find answers to these questions. Subsequently, in 1973 and 1974, a grant from the Australian Institute for Aboriginal Studies and a Visiting Fellowship in Anthropology from the A.N.U. enabled me to extend the investigation into the Western Desert, under the tutelage of men most of whom had spent their youth as nomadic stone age hunters. What they taught me makes up the bulk of this paper and provides some sort of answers to our opening questions.

The author, a Master Mariner and Section Chief of the All-Union Research Institute of Marine Fisheries and Oceanography, Moscow, U.S.S.R., deals with the principle of clockwise rotation of the line of relative motion, as applied to simultaneous encounters with several ships. He presents arguments for a strict compliance with the well known dictum of Captain Oudet: ‘Encounters at sea are governed in such a way that each party knows what he should do and what the other should do.’ The paper was written in collaboration with the late Captain G. Shoomayko.

It is commonplace nowadays to assume that modern technology is rendering inevitable the demise of the traditional navigator—in the commercial shipping world at least—and there is much discussion of what this can signify for the future. Yet at the same time there is no little confusion over what is meant, and will be meant, by the term ‘Navigator’. In the context of the Merchant Navy the truism can be made that all deck officers are navigators, and indeed that navigation has been a prime source of satisfaction to many of them; but very few are or ever have been lifetime navigators to the exclusion of all else. Certainly there are the small bands of hydrographers and specific navigators engaged in such fields as offshore work needing a high degree of accuracy, whose prime job in life this is. But they are a select and specialised group whose existence does not negate the view that for the majority of deck officers their navigation is at best part of a wider whole. So to talk of the demise of the navigator is misleading; no deck officers on merchant ships will be out of a job simply because navigation becomes less important. What they will lose is a most interesting part of their work.

Commander Haines examines the more stringent navigational requirements of fishing vessels, reviews the instruments in use, both radio and acoustic, and discusses the significance of a number of navigational factors, such as speed over the ground when trawling and the avoidance of obstacles on the sea-bed. The paper was presented in London on 14 May 1975 with the President, G. E. Beck in the Chair.

In this note I wish to enter however belatedly into the discussion of error distributions in navigation (cf. Anderson and Anderson and Ellis). Not being a navigator my arguments will be purely statistical, but I hope that they will throw some light on the problem, which seems to be an important one.

Hampton and Mills have commented that large errors occur more frequently than is predicted by gaussian behaviour; and Anderson remarks that in practice the ‘skirts’ of the empirical distribution are commonly hitched high over the estimated gaussian tails. The conclusion drawn is that navigational errors follow a distribution closer to the two-sided negative exponential than to the normal though, instead of peaking to a sharp point at the centre, the empirical distributions seem to have rounded heads.

A simple method is described for estimating the angle of misalignment of a two-component electromagnetic log, using the covariance properties of the measured components when a ship is steered in a constant cross wind at a number of different speeds. It is shown that, with the present accuracy of radar fixing, allowing for misalignment has a very small effect on the determination of sensitivities for an absolute calibration. However the effect of misalignment is important when cross-calibrating the athwartships components of two electromagnetic logs.

The rapid developments of mini-computer technology and the introduction of integrated navigational electronic equipment in ships calls for a reappraisal of bridge design as a matter of urgency. Several research projects have been carried out in recent years and all have concluded that ‘a completely fresh outlook is required rather than work on existing designs and on methods which are regarded as both accepted and acceptable’. Shipowners and shipbuilders need to understand the requirements of the men who will be responsible for the safe handling and navigation of the ship and to choose between stagnant inefficiency and economical gain through proficiency. The standard central command-post layout design should comprise flexible units adaptable to every type of merchant ship, except of course such specialized vessels as oil rigs.

Most authorities are agreed that detailed plotting is an essential part of a ship's radar collision-avoidance system, and teaching on the subject includes the calm intellectual detachment of the radar simulator; with First and Second Officers respectively to plot the data and evaluate the developing situation, decide upon the appropriate action and initiate the conn. In conflict with this ideal executive bridge manning concept is the increasing tendency towards automation and resultant crew reduction, to the point where in an increasing number of vessels (in particular the ever increasing number of specialized supply vessels in the offshore oil industry) spare capacity no longer exists to permit the separation of bridge functions such as lookout (Rule 29), radar observer, radar plotter and anti-collision conning. The dictates of low manning, long hours and arduous and often dangerous work on low freeboard, heaving sea-swept decks, all combine in such vessels to restrict bridge manning to a single navigating officer—as a rule on a six-hour shift—overseeing the gyro-steering, reading out and plotting from the position fixing system, operating the radios, keeping a weather eye on the various bridge-mounted engine gauges, observing the radar and, when necessary, overriding the gyro steering to manœuvre the ship manually in any collision-potential situation. Radar plotting is seldom undertaken in this class of vessel, there being a limit even to the accomplishments of the one-man-band.

Professor M'Pherson's paper on ‘Education and the Sea’ does somewhat less than justice to the non-university sector of the British educational system; his Appendix A lists only two university undergraduate courses in nautical—maritime studies, whereas six such courses are offered by polytechnics and the first of these was approved ten years ago.

More recent developments have included a B.Sc. in Fishery Science; a number of degree courses in Environmental Studies and Geography, which contain substantial elements of meteorology, oceanography, cartography and marine surveying; and post-graduate courses in Shipping Management and in Hydro-graphic Surveying. These courses gain awards of a first degree or the diploma of the Council for National Academic Awards—a body which deserves much credit for encouraging experimentation in many ‘new’ areas of study.

If I may continue Mr. Harrison's analogistic extravaganza for only a moment, I would like to say that whatever smoke, haze or fog there may have been in his vicinity it has prevented him from identifying the target at which I and my colleagues have been firing. I must also say that his bland assumption of the superiority of his own gunnery is hardly complimentary to the highly qualified and experienced support without which, as he well knows, no simple sailor would venture into such a technical action.

None of my comments made upon this subject thus far have denied the existence of errors, cyclic or otherwise, in the sources from which the radar data is drawn; nor have I disagreed with the evidence and the theories about the size and character of such errors, and the resulting prediction errors they might cause, which have been adduced by the various experts (in electronics), under the conditions and within the limits which they postulate.

The small-craft navigator is beset by a number of problems in taking sextant observations; of these wave motion is foremost for the constantly changing height of eye makes the dip correction uncertain. One alternative is to take a number of sights and average the times and altitudes; but averaging angles, and especially times, is an error-prone occupation and if one of the sights is badly in error it will probably not be noticed, and will bias the resulting average. This would be avoided if all the sights were individually reduced and plotted, but the work involved is prohibitive. The method here described permits several sights to be taken and the individual position lines plotted, but requires practically no increase in work over a single sight. Inspection of the position lines will give a very accurate average and also indicate immediately if one of the sights was in error either in recorded altitude or time.

Mr. Podmore's article1 will certainly cause several people to write to you, as he is not suggesting the best use of the HP-35. One advantage of the Hewlett-Packard calculators is that one does not need to convert degrees and minutes to degrees and fractions of a degree before beginning the problem. Also one should use the cosine law again to find the azimuth. The usefulness of the calculator is that it can find with ease, both the calculated zenith distance and azimuth (no more tables!).