I started navigating before yacht Decca became available, and although I like to think I did a competent job, it was a revelation to be able to press a button and get not only an accurate Lat and Long, but also reliable values to all the variables like tidal effect and leeway, which before Decca were at best an educated guess.
And then came GPS, even more instantaneous in response, and not as temperamental as Decca. But where do you draw the line? From welcoming GPS on board, it's a small step to a chart plotter, online weather updates and all the rest.
If you're going to watch it all on TV, you might as well stay ashore, some old salts argue, and maybe they have a point. But there's still the safety issue. Radar and chart plotters have plummeted in price, and are now within the scope of quite modest family cruisers.
We had our first taste of both when we swapped our purist racing boat for a performance cruiser. It came ready equipped with a high spec Raymarine Seatalk network, including two radar and chart plotter screens, one at the nav station and one at the wheel.
Getting the hang of the plotter was easy: only a small step on from programming the GPS, and much more user friendly, because you can, literally, see what you are doing. But to the complete novice, radar can seem daunting and confusing, with so many new technical terms and concepts to grasp.
Gain, range, clutter, snow, rain, wakes, VRM (variable range marker), EBL (electronic bearing line), guard zones - you can become blinded with science, struggling to make sense of a bewildering display of rings, dots and dashes. But having got the kit, it would be silly not to learn how to use it, and we gave ourselves a thorough “teach yourself” course one day, manual in hand, while motoring across the Thames Estuary in no wind and endless visibility.
We quickly learned to interpret the blobs on the display, to tell the difference between a buoy and a boat (made even easier by the capability to overlay the radar echoes on the chart display).
We discovered, too, the helpfulness of radar in predicting rain. We saw the shower cloud looming over the horizon coming towards us on the screen, too - providing an all-too accurate answer to the perennial question: is it going to miss us?
Best of all, we discovered the value of Marpa (Mini Automatic Radar Plotting Aid). The networked electronics compute our speed and course against multiple selected targets to tell us not only how fast and on what bearing each ship is approaching, but also the time and distance of its closest approach.
Obviously, this must not be trusted absolutely. The much-discussed danger of “radar assisted collision” cannot be ignored. But it was very confidence-inspiring to compare the computer calculations with the evidence of our own eyes and find the two in very close agreement.
We'd still sooner not put to sea in bad visibility, but there are times when you get caught out. And there are times when deadline pressure forces you to set out in less than perfect visibility.
We had just such a day last summer, leaving Cherbourg on a very murky morning heading for Fecamp, on the way home from our holiday cruise to the Channel Islands. There was very little wind, so we motored along with the Autopilot steering, while one of us watched the radar and the other kept an old-fashioned lookout.
We blessed the original owner of the boat for putting the second screen at the binnacle. Far better than sacrificing one pair of eyes on radar watch down below.
“There should be a fishing boat or something small a couple of miles over there,” announced the skipper - and sure enough, a trawler soon appeared out of the gloom, just where he was pointing.
Bad visibility undermines your ability to judge distances, and it was reassuring to learn from the screen that at the point we could properly see it, the fishing boat was just over a mile away.
Confident that we could see for a mile - and the electronics considerably further - we set out across the Seine bay. We knew the first large ships we were likely to meet were the ferries out of Ouistreham, and sure enough, the radar found them, one going in and one coming out.
By the time we reached the approaches to the supertanker terminal at Antifer, and the cross traffic on its way to Le Havre, thankfully the visibility had improved as forecast, and the evening sun was trying to get through.
But what might have been a miserable day - motoring along in the murk, straining to keep a lookout - had been transformed into a much more positive experience. The technology had done exactly what it should - provided useful information and reassurance - and we'd enjoyed honing a vital new skill. We've very quickly learned to love our radar.
(Taken from an article that first appeared in the magazine Norfolk Afloat.)
