I wrote the bones of this article about a decade ago but even over that shortish space of time technology has advanced mightily. When I first crossed the Atlantic in 1974, the sextant shown here figured prominently. When I crossed in 2015 it languished in its box the whole way across. But that's nothing compared to what the old-timers were faced with.
At about the same time that William Gladstone was serving his last term as Britain's Prime Minister a yachtsman named Richard Turrill McMullen was publishing his reflections on over 40 years of cruising along the English coast. The book, Down Channel, originally emerged in the early 1890s. It included a foreword by Dixon Kemp, yacht designer and ‘yachting editor’ of The Field. A later edition had an intro by Arthur Ransome, the Swallows and Amazons author.
A quotation from McMullen's book gives a fascinating insight into the spirit of sailing in those days:
"…then laid course for Fowey, which we made at 11pm. Being unaccustomed to high black cliffs, and having no other means of ascertaining their distance - for mere appearance is very deceptive - I resorted to a powerful copper whistle, and estimated the distance by echo."
Although displaying some unconscious prescience of modern radars and depth sounders, McMullen was, of course, only taking advantage of the speed of sound (about 340 metres per second at 15°C or, with a nod towards our American pals, 372 yards at 59°F). We can imagine him on the foredeck, hand cupped to ear, waiting for the echo to return. Since the sound would have to bounce off the cliffs and come back, a one second delay would have placed him 170 metres off -- though the accuracy of judging such intervals must have been very questionable. All the same, it gave him an indication. If there had been no echo at all, he might have told himself that he was further off than he thought, perhaps encouraging him to stand on until a response was audible.
And neither was our redoubtable skipper being particularly ingenious, for this was a common wheeze amongst sailors -- a musket shot often being employed when such was at hand. In daylight, another possibility would have been to use the earth’s curvature. It’s readily understood that the higher your viewpoint, the further away lies the horizon and vice-versa. This principle can - and was - employed for judging the distance between an observer and, as a substitute for a horizon, the white froth of waves lapping on a shore. By raising and lowering your height of eye until the waves are just visible, you can calculate (think Pythagoras) or consult such nautical tables as Norie’s to determine the range. As examples: at a height of eye of 19ft (5.8m) the breakers will be 6NM away; and at 12ft (3.66m) just 4NM. More relevant since this applies to many helm positions - if seen from a position 5ft (1.52m) above the waterline, the shoreline will be 2.5NM distant.
In the absence of the sort of pinpoint position finding we take for granted today, earlier navigators involved themselves in a deductive process that involved much more than meticulous dead reckoning. If blown off course or eclipsed by poor visibility they frequently ‘lost their bearings’ and slowly had to gather together what information they could to re-establish their whereabouts. If the sun was visible, there was always the sextant, but that’s not something you can count on in these latitudes. In 1970, I ferried a sextant all the way around Britain and, thanks to cloud cover, never had a single opportunity to use it.
Now, I’m not in the least bit nostalgic for those somewhat hit-and-miss times. Generally, I’m delighted with the wonders technology has brought and wouldn’t wind the clock back for all the rum in Grenada. And neither would I relish a return to blasts from powerful copper whistles - let alone muskets - nor the vertical calibration of eyeballs while peering at the shore. But, all the same…
But, all the same, I do wonder what would happen if the micro-marvels betrayed us and we were forced back onto past skills. So, my resolution for the 2017 season is to spend at least part of my time doing it the old way: to reacquaint myself with dipping lights, running fixes, doubling bow angles, my woefully neglected sextant and the sight reduction tables that go with it.
At least, that’s what I think I intend to do.