About 15-20 years ago, when GPS started to become ubiquitous, it was not uncommon to hear about GPS assisted groundings where a skipper set a waypoint here, and a waypoint over there a few miles, and forgot to look at the shoal or headland between the two waypoints. So much so that the Power Squadron Piloting course segment on GPS navigation was changed to teach folks to avoid the situation.
Then when GPS accuracy increase significantly, there was rash of GPS assisted collisions with objects. I had a friend, a two time circumnavigator with decades of wxperience, who used a channel market for a waypoint and left a big blue paints stripe on the marker as his boat scraped along side. And a far less experienced local was bringing his new-to-him Bermuda 40 home under full sail, using all those expensive instruments to steer the boat, when he ran head on into a channel turning marker mounted on a dolphin made of 3 12" telephone poles. Actually I was really impressed by the Bermuda 40, which had bent the polished stainless CQR and the bow pulpit when it hit the dolphin, but which did not even crack the fiberglass of the boat. Again the course was changed to teach offset waypoints. Now you hear about the occasional collision between boats using almost the same waypoints to steer a route. And on my recent delivery up the ICW from Port Royal to Pamlico Sound, I saw an uncomfortable number of boats who seemed to be following the "Magenta Line" with no one at the helm. I can recall several stretches of the ICW where I was firmly in the middle of the cut, but the boat icon was in the weeds on the chart and the Magenta Line was a fair bit away from it. At times like that is is good to recall that the positions shown on the chart were determined 25, 45, 65, or more years ago by using methods far less accurate than GPS. Makes sense that the warning on electronic navigation devices say they should not be your only means of navigation. The rule should be that you be at the helm and keep your eyes out of the boat. Maybe the GPS should have a button that needs to be pressed at random intervals of 2 minutes or less, and if not pressed the boat stops. Think of it as a sort of "deadman switch" for the terminally stupid boater. From: CnC-List [mailto:cnc-list-boun...@cnc-list.com] On Behalf Of Dennis C. Sent: Wednesday, January 15, 2014 4:44 PM To: Cn Clist Subject: Stus-List Setting GPS Waypoints (long) I made a transit with a learning sailor who had just bought a new handheld GPS. It was a lower priced model with a map but not a true chartplotter. He wanted to see The Rigolets, the outlet of Lake Pontchartrain, so he wouldn't be intimidated should he ever do it himself. As we made turn after turn along the route, I noticed he wasn't setting any waypoints in his GPS. I mentioned it and he said he didn't need to because all the marks were in the pre-loaded database in the GPS. I suggested to him that it might be a good idea to have waypoints set in the middle of the channels where he wanted to turn rather than using the fixed marks that lined the channel. He thought about it and then the light came on. On another occasion, I helped a friend bring his new boat home from across the lake. It had a nice Raymarine charplotter. Imagine his amazement when, as we motored down the middle of Mandeville Harbor, the symbol for the boat on his chartplotter went through the middle of the seawall on our port side. What if the visibility had been zero and we were totally relying on the chartplotter? I have a waypoint set a hundred yards or so off the entrance. I can arrive at the mark then feel my way into the harbor entrance in low visibility once I have visual contact with the lights or seawalls. I have two fixed mount GPS's and 1 handheld (kept in a waterproof pouch with the batteries removed). The fixed mounted GPS's are at the helmstation and navstation and are routed through a switch so that one or the other is interfaced with the instruments and autosteerer. Anyway, relative to the subject line, ALL the waypoints in my GPS's are OBSERVED, That is, I took the boat to the spot where I wanted the waypoint and hit the "Mark" button on the GPS unit. If I'm not comfortable with it, I've been known to swing the boat around and go back and re-mark it. I always delete the other one. If I'm going somewhere new, I may enter a waypoint from a chart but once I reach that point, I may adjust it according to where I really want it when I observe the conditions at the waypoint. I'm always amazed at how many boaters use government marks, bridges, etc. for waypoints. For instance, I set a waypoint on either side of a bridge opening. I don't want to use the center of the opening. Never know when you're going to arrive in a thick fog or other adverse conditions. Government marks, buoys, bridges, etc. are things to be avoided, not to be used for waypoints. My mid-channel waypoints are set such that I am well away from points, shoals, etc. If I need more than one waypoint to navigate safely around a bend, I set them. I can always cut the corner in good visibility. So, the next time you enter a waypoint in your GPS, ask yourself "Is this REALLY where I want my boat to be in zero visibility?" Still, having waypoints you are comfortable with doesn't relieve you from maintaining a diligent watch or totally, completely trusting them. Remember, aids to navigation and navigational aids are used to help you, the boatowner, skipper, to properly navigate. I still have paper charts on board and, although I don't have a sextant, I do know how to determine my position by triangulation using a hand held compass and charted objects on the shore and waterways. The paper charts are always out for reference every time I make a long passage. Dennis C. Touche' 35-1 #83 Mandeville, LA
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