As a boat based electronics concept, GPS (Global Positioning System) has revolutionised the sailing world. There are no two ways about it. For offshore fishing where absolute precision can be key, at a stroke it has removed one of the biggest constraints to consistency. Obviously there are safety implications to the story too which are in no way being understated here. But it is as a navigational aid to finding or re-visiting fishing marks, and getting back to base afterwards, that its everyday use really comes in to its own. Okay, so electronic navigation in other guises was around before GPS. We had Decca and later Navstar which converted Decca signals into Lat-Long coordinates. The drawback was however that these were vulnerable to the vagaries of prevailing atmospheric and meteorological conditions which could greatly reduce the accuracy of their signals, and even at times temporarily take them out. Having a sky based satellite system does not totally remove these problems, but there are ways of getting around these and other signal blocks such as AGPS, DGPS and WAAS. AGPS (Augmented GPS) uses wireless and cell masts to help relay satellite signals where they cannot get through. DGPS (Differential GPS) combines the above with satellite signals and calculates the differential between the two for greater accuracy, which can be particularly useful when atmospheric conditions are poor. Finally WAAS (Wide Area Augmentation System), which is primarily used for aircraft navigation. And it was aircraft navigation that was to be the key player in making GPS available for civilian use after it had been developed as a guidance system for Intercontinental Ballistic Missiles (ICBM's) during the cold war. The shooting down of a Korean Airlines jet that had strayed into Soviet air space prompted Ronald Regan to bring GPS into the public domain. Having said that, the signals were deliberately degraded for non military use until 2000 when Bill Clinton ordered that the degrade switch be turned off making full strength GPS available to everyone. On top of this, because it is not land based, GPS is truly global. As they say in the adverts, it does exactly what it says on the tin.
Out there on that vast expanse of same looking grey open sea, without GPS, precision would be extremely hit and miss. Try looking at land marks in transit, even using two or three in line, then carry on motoring for say another 50 or 100 metres and see how little the supposed position changes. Obviously, the closer you are to shore, the more accurate landmarks become. But what about when there is fog, mist, or rain masking your view, and when you are working out of sight of land. Without GPS the possible becomes impossible. And what if, God forbid, you have a sudden power failure and are left to your own devices. Most people these days are so reliant on their GPS that they no longer carry a magnetic compass. I remember the maiden voyage of our Warrior 170 at at Cleveleys on a day marred by freezing fog. Having started to motor off, we suddenly remembered that the memory in our new GPS was empty and that we needed to use the Man Overboard facility to store our start point for the return leg. We only looked down at the instrument controls for a minute or so as we located our current position as a fixed way point. When we looked up again, with the fog being so dense, we were completely disorientated to the point where we had to look at the magnetic compass literally to get our bearings again. We had absolutely no idea whatsoever which way was land and which way was open sea. Imagine then loosing power to your GPS and becoming similarly disoriented out at sea with limited reserves of fuel, worsening weather, and/or dangerous obstacles in the vicinity. It doesn't bear thinking about.
Only a fool goes to sea without a magnetic compass. Running the compass a very close second is having a portable electronic backup in the form of a hand held GPS. Extravagant??. Well not when you consider the potential consequences of our almost total reliance on GPS these days. And equally not extravagant when you consider the price of these units now, and the many other potential angling uses they can be put to in addition to their backup role. Let me give you a few examples. One I have just completed was a visit to our launching beach in front of the Royal Hotel in Cleveleys at low water on one of the biggest tides of the year. Because of shifting sand patterns locally due to new sea defence work, a huge boulder groyne has been constructed yards away from the end of the slip. So getting a fix on the seaward end of this hazard for coming it when it is covered was job number one. We then walked right down to the lower shore in front of the slip to take a second reading as our turning in point. In addition to this, when coming in towards low water, you can get grounded here out of reach of the tractor and trailer, separated by a deep gulley at which point you then need to wait around until it empties. But, if you can find the way into it, it's possible to sail parallel to the shore a hundred or so yards off and get right up to the sand. So we walked the gulley way-pointing a route to the end including the entrance point. We also noted areas of boulders and rocks which need to be avoided at certain times, and the biggest clean area of safe sand we could find as a landing target. Back in the boat, you could take it fishing in situations where access to GPS otherwise might not available. It could be someone else's boat, or more likely a self drive boat, and in that respect, my little Garmin will prove extremely useful for a planned trip to Scotland fishing from self drives in Loch Etive and Loch Sunart. Plotting potential shore marks at low tide is another use, as is taking it on the shore when fishing in areas where there are no land marks at night to head back to. Talacre Beach in North Wales is a good example of this, and indeed has seen fatalities when shore anglers have become disorientated and ultimately lost. Finally, one cynical example that has also been suggested is taking it on charter boat trips to 'borrow' their peoples marks which something I am sure does already go on.
The hand set I use is the Garmin 72H which is a rugged fully waterproof unit with great versatility and ease of use. It supposedly even floats, though I think I'll take their word for that one. The overall dimensions are quoted as 2.7 x 6.2 x 1.2 inches with a high contrast 1.6 x 2.2 inch screen boasting a resolution of 120 x 160 pixels. All operations are conducted using eight clearly labelled push buttons and a four way rocker switch located just above the screen offering up to 500 waypoints, 50 routes, and a point track log with 2048 points and up to 10 tracks. Powered by two AA batteries, the unit will operate continuously for up to 18 hours before they need replacing, and has an operating weight of 8 ounces. Page one gives a mix of information including satellite status, accuracy, elevation, date, time and current position. Page two is a map page with an overlay of lat-long numbers and a course to steer guide. Page three is the compass featuring a compass rose, speed over ground, and distance to waypoint, followed by page four which again gives speed and distance, plus course and off-course information. The final page is the active route page which displays current waypoint information. It also has a man overboard facility for grabbing quick fixes on specific spots which could include fishing marks and other points of interest picked up on the hoof and storing them. All in all, an easy to use, easy to read, reliable pocket sized back up with a whole range of other uses outside of simply being a backup unit.
