NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: DR navigation in the recreatiional fleet: was Role of CN at sea
From: Jim Thompson
Date: 2004 Oct 13, 08:33 -0300
From: Jim Thompson
Date: 2004 Oct 13, 08:33 -0300
I know we discussed this some last year, but the issue remains unclear in my mind. How should GPS navigation be taught to recreational boaters who have minimal or no traditional navigation training? I've thought about this issue a lot, partly because I was well grounded in traditional coastal DR piloting, and partly because I am now involved in the Canadian Power & Sail Squadrons' teaching programs. We are struggling to figure out how to deliver safe GPS training to recreational boaters who don't want to spend a lot of time learning navigation. All my navigation now is within sight of land, except for short times when mist, rain or fog reduce visibility. Boaters with minimal navigation training can go to Canadian Tire, buy a GPS (handheld or chartplotter), and had out into the water. And they do, by the thousands in North America. Those folks for the most part are not interested in learning the intricacies of running fixes, leeway, and DR/EP plotting, and it is darned hard to convince them why they should (even though I believe they should). I taught a one-day GPS course a couple of years ago where I referred to such topics. The evaluations largely suggested that I drop those comments from the course. But can marine GPS navigation be properly taught to beginners who know nothing about LOP's, fixes, courses and tracks? GPS has changed the way recreational boaters navigate, particularly as we become more comfortable with its startling accuracy and reliability. My personal experience is that I use a GPS chartplotter exclusively, but mentally I continually maintain a kind of DR plot in my minds' eye, using data from my eyes, compass and sounder to verify the GPS postion and to help me decide on course changes. I also use radar, even in good weather. There is nowhere on the boat for me to lay out a chart and draw all the lines and symbols that I learned in traditional piloting, but I keep a current chart in a large plastic envelope on the bridge and refer to it often as we proceed. If I know from tide tables and the chart that the tide is running right to left, then I adjust my course to compensate accordingly. Same with the wind (leeway). The "tail" on the GPS chartplotter tells me how much leeway and current I am experiencing, and shows me whether my compensation is effective. But I am doing all that in my mind's eye after years of training in traditional coastal piloting. But I wonder -- is that how the lesser trained boaters are navigating with GPS? I listened to a long exchange on marine radio this summer that makes me think not. I still think that boaters should learn EN by first learning traditioanl piloting. They might never use parallel rules again after completing the course, but they will certainly know better how to use GPS. By the way, I have never experienced GPS drop-out on the Canadian Atlantic coast in the past 5 years, unlike the experience of the Lakes boaters. Jim Thompson jim2@jimthompson.net www.jimthompson.net Outgoing mail scanned by Norton Antivirus ----------------------------------------- > -----Original Message----- > From: Navigation Mailing List on Behalf Of Federico Rossi > The point is that GPS navigators (I'm talking about boats and not > cruisers) sometimes seem they have forgotten DR principles, they regard > the practice of estimating and checking their position with the well > known methods of coastal navigation (and why not, of celestial > navigation) as a waste of time, thus losing the opportunity to interpret > the effect of the currents, of the wind, the behaviour of the boat, and > to forecast the corrections needed to follow a certain route (and > eventually to cross check their electronic instrumentation).