The boat is just the beginning. Once you have acquired that 35-foot sport-fisherman, that tall and graceful auxiliary, that offshore trawler gone yachty or even that jaunty little outboard runabout, the question becomes: How much navigational equipment can you afford to pile on board? The exhibitors' booths at boat shows all over the country will soon be twinkling and beckoning with electronic gadgetry shiny and appealing enough to make a yachtsman's mouth water like a child's before a Christmas tree. It will be no time to remember that Columbus made it across the "western ocean" with little more than a magnetized needle and a lead line. Ship-to-shore telephones (below), radio direction finders, radar, autopilots—the modern boatman thinks them all as vital to existence afloat as his life jackets. It was no virtue on the part of Columbus, says the modern sailor, but only good luck that he was able to pinpoint his position in mid-Atlantic without a loran like that on the opposite page. There was bad luck, too—Columbus could not study the contours of the ocean bottom and find a school of fish for dinner with an electronic depth-sounder, nor could he turn his helm over to an automatic pilot guaranteed to steer a truer course than any quartermaster. Thanks to the nautical gadgetry pictured here and on the following pages, any landlubber can now put to sea better able to find his way home than a motorist on an unmarked cloverleaf. And he will have the joy of owning some of the prettiest toys ever conceived.
Loran (meaning long range), the most sophisticated of all electronic aids, is designed to give the navigator an accurate position fix from stations up to 1,400 miles away. Each loran master station broadcasts a series of pulses, which is picked up and rebroadcast by one or more slave stations. The shipboard receiver picks up both of these signals and measures in microseconds the difference in time it took for them to arrive. From this measurement the navigator is able to place his boat along a hyperbolic line of position already marked on deep-sea charts. The intersection of any two such l.o.p.s determines his position.
Omni (above), short for omnidirectional visual range, the newest and in some ways the best of the boating electronic aids, was developed for flyers. A refinement of the old airport beam, it consists of a network of stations, each broadcasting a full circle of 360 beams that can be instantly identified on the dial of the receiving set. A navigator therefore only needs to tune in two stations and read off his bearing from each to get a positive fix. Though limited to line-of-sight reception, Omni is far quicker and more accurate than the rotating antenna system of an ordinary radio direction finder like the one pictured at the left.
By now most Americans have become familiar with the luminous "blips" that appear on radar screens like the one shown below. These are, in reality, the electronic echoes of radio pulses sent out from the radar to bounce off objects ahead. The depth-finder at left of radar set works on the same echo principle. A device called a transducer, set in the boat's bottom, sends pulses down, then the indicator measures the time it takes for echoes to return. These measurements are translated into depth in feet and are shown on a dial on the boat's bridge. The small red lines at 15 feet indicate a school of fish; the bolder red line at 35 feet is the sea bottom.
Unlike an ordinary radio direction finder (RDF) whose loop antenna must be aimed manually at the broadcast source to determine its direction, an ADF, or automatic direction finder, gives a direct reading of the station's bearing on a dial calibrated in compass degrees and minutes. Like the RDF, it can tune in on virtually all kinds of broadcasts and hence use all manner of stations and beacons as landmarks from which to establish a line of position.
Hidden below decks, the small binnacle is the heart of the automatic pilot pictured at left. Once the course is chosen and the pilot turned on, a tiny photoelectric eye in the binnacle fixes on a compass card, watching it for any slightest change of course. When one occurs, it signals the power-steering mechanism to correct with right or left rudder. The skipper can, if he likes, countermand the autopilot's orders with a hand-held "dodger" to steer around a piece of driftwood, but once he lets go it again assumes its rigid command.
While the money a man can spend on navigational gadgetry is almost limitless, the transistor age has made it possible for the moderately well-to-do skipper of the Susie Q to equip his bridge with gear once seen only aboard vessels like the Queen Mary. When loran was first introduced, for example, an adequate installation weighed hundreds of pounds and cost well up into the thousands. Today you can get a fully transistorized loran (Model CA 400A) from Raytheon for a mere $1,775, and it is capable of doing almost anything the Queen Mary's loran can do. It weighs only 25 pounds complete and runs off a 12-volt battery. If the price is still too steep, you can get a cheaper model from Enac/Triton, with a range of 700 miles, for only $1,195. It weighs only 15 pounds. Even better than loran for the short haul, Enac/Triton's omnigator can be had for a trifling $895.
Since omni broadcasting, like television, can be transmitted only from antenna to antenna in a straight line, its use is limited to 40 miles or so from the beaming station. Even this limited distance may be reduced unless your antenna is mounted on a high enough mast. Triton, the leading maker of omni, suggests a minimum of 35 feet. Moreover, since it began as a navigational aid for aircraft, omni is still largely dependent on stations located to serve the air rather than the sea.
Far cheaper, more compact, less accurate but still a vital aid to the small-boat sailor caught out in a fog is a whole family of radio direction finders, which range in price from $90 to $500. Basically these instruments are simply multiband portable radio receivers with loop antennas that can be swung around an arc to aim at whatever broadcasting station the set is tuned to. When the antenna is lined up with the station, the sound dies to a minimum (called a null) to give the operator a bearing on that station. Besides pointing the way to shore, these little RDFs can be used to pick up a sailor's favorite disc jockey or news broadcast on the regular band, Coast Guard warnings, ship-to-shore phone conversations, weather reports and special radio beacons on the other bands. Any broadcasting station can be used to obtain a bearing, but the accuracy of the final fix depends to a great extent on the sophistication of the instrument being used and the skill of the navigator using it. And all are subject to such vagaries of broadcast transmission as the "night effect" that deflects some radio waves after dark.
Automatic direction finders (ADFs) perform much the same function as the RDFs, but they are more complicated and hence far more expensive. The cheapest ADF runs about $1,100, the most expensive around $1,600. One of the handiest is Enac/Triton's ADF-360, which, unlike most sets, combines the direction-indicator dial and the radio receiver in one compact unit, measuring only six inches high, 10 deep and 11 wide. Its tidy shape makes it ideal for small cruising auxiliaries, where space is always at a premium, and its price is only $1,195.