About - Navigation Electronics

From time immemorial the principal problem of navigation has been 'knowing where you are now'. With the advent of inexpensive and highly accurate Global Positioning System (GPS) equipment there is no excuse for navigators to not know where they are. We have a, now old, Garmin GPS that has led us around the north coast for years and we would not leave home without it.

The key to good performance form GPS on a boat is an externally mounted antenna with a clear view of the sky.  Our initial experiments with the built-in GPS antenna running inside the cabin of the boat prompted the quick purchase of an external antenna.  The unit has performed flawlessly since.

The US government has recently removed the "Selective Availability" built-in error from the GPS System. The accuracy is now down to about fifty feet anywhere in the world. Any discrepancies between the chart and the GPS are probably due to inaccuracies in the chart. It is truly remarkable to see the chart plotter tied to the GPS, display our mid channel course through a 100 foot wide passage in the middle of nowhere.

If you travel the north coast in the summer there is one given: You will find yourself in the fog at some point. With a GPS at hand and someone diligently plotting positions on the chart you can find your way around quite well.  In fog, however, your prime concern should not be 'find my way around' it should be 'avoid getting smashed to splinters by something much larger than me.'  Wandering around in the fog out here in one of the busiest shipping channels in the world is asking for it.

If you do get caught out without radar, get on the radio to Vessel Traffic Services (who you should be monitoring). They will advise you of any reporting traffic ( read 'things that are big enough to squish you like a bug' ) in the area and will advise nearby vessels of your presence. Don't be shy, just do it.

N'uf said... Off to the Radar store. A 24 mile enclosed radome model with the best short range performance available. Mount it high, with an unobstructed 360 degree view. And pick up the biggest radar reflector you can find while you're there.

The best, and first investment you should make for cruising the north coast is a good autopilot. When we acquired Shelyann we bought new NAV electronics and a pilot before heading north that first year. The pilot didn't get installed until we made Port Hardy and when it was up and running the difference was like night and day.  

Rather than one of us constantly tending the wheel, the pilot flawlessly maintained whatever course we set it to. Traveling all day became a joy rather than a chore as we could wander around the boat and do whatever, as long as one of us was watching the water ahead.  In fine weather I often navigate while standing on the after deck which has a clear view ahead through the cabin, only going to the wheel to dodge around whatever obstacles appear.

In fog, the autopilot is a great help. It is very easy for the human brain, in a moments inattention, to get off course or 'turned around' without any visual outside references. The pilot doesn't care about fog, it will maintain whatever course you set it to. It has proved invaluable in maintaining a steady course while navigating in tight quarters when the skipper is distracted by the chart and the RADAR.

Every vessel should have a marine VHF with a properly mounted external antenna. We use a Standard Radio model mounted at the steering console that has a remote microphone and speaker in the console on the upper deck. We also have a waterproof hand-held VHF radio that we always carry when we are off in the skiff.
Chart Plotter:
The best thing since sliced bread.  It is all well and good that you have a GPS siting in front of you telling you your latitude and longitude to the 1000th of a degree but that doesn't tell you how far away you are from that rock.  With the GPS tied to the charts on the computer you have a running plot on the chart of exactly where you are. When navigating in close quarters it is invaluable to see moment-by-moment your position relative to the surrounding real-estate



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