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The author outlines some of the history of navigation and brings out the status of the navigator among the Polynesians. His theme is that life will not be the same when the sextant and the Polynesian palu's knowledge are replaced by an electronic device depending on the Global Positioning System. >

Most shipmasters making a tortuous passage through a strait or among reefs and islands, after a long passage on one course in a vessel equipped only with magnetic compasses, are worried out of all proportion to the hazards of the manœuvre by reason of not knowing in all certainty what compass errors will pertain on widely different courses. Of course there is the Azimuth Record Book, but the last time similar courses were used could have been in the other hemisphere or under different conditions of trim, &c.Given time, weather conditions and other suitable opportunity a prudent master will have conducted a swing to ascertain the errors before approaching the stretch of dangerous water. This may not be possible and, again, he knows in his mind that azimuths taken under these circumstances, with little time to waste, do not always conform to the later findings.

The full value of A.P. 3270 (Sight Reduction Tables for Air Navigation, Vol. I, Selected Stars, H.M. Stationery Office) does not yet seem to have been fully appreciated by surface navigators. As well as increasing the speed with which sights can be reduced, the tables offer all the advantages of a star globe or planisphere in planning a series of sights. The navigator can thus concentrate on the most suitable stars for cut, magnitude and azimuth. Since observations can be planned for a time at dusk when the horizon is still firm and the star just visible through the telescope (or, at dawn, when the star is still visible and the horizon firm), a more accurate sextant altitude can be obtained.

The civil aviation problems in training navigators may appear simple compared with those of our marine colleagues, and possibly also in comparison to the military side of aviation. In civil aviation we are concerned with tactical problems but not to the same extent as in marine and military aviation, but there are those amongst us who can recall the halycon days of flying boats when we too were concerned with the tides and the state of the water. Since the end of the war there have been far reaching changes in civil aviation and navigation. The object used to be one of getting from A to B and battling a great deal with the unknown—long night hauls across the North Atlantic, Shannon and Keflavik, icy cold arrivals at Goose and Gander, pressure pattern flying and so on, with the minimum of navigation equipment, poor weather forecasting and limited range aircraft. Nowadays civil aircraft range is not the problem it used to be, although some such problems still exist, navigation equipment is more sophisticated and the A.T.C. requirements much more stringent. It is not so much getting from A to B as staying as close as possible to an assigned A.T.C. track.

Sixteen pilots of two widely different expedience levels were tested on an area navigation task involving approaches with two levels of navigation procedural complexity. Two types of displays were used for leveloff at MDA, command leveloff and an altimeter. The four recorded performance measures were vertical steering, horizontal steering, airspeed control, and procedural accuracy. The less complex approach procedures (Simplified) resulted in better performance on all four recorded measures than the more complex procedures (Standard). However, no reliable performance differences were evident between levels of pilot experience and types of leveloff displays. In comparison with previously assumed values of flight technical error, Standard Procedures generally yielded larger errors, and Simplified Procedures generally smaller errors.