Re: GPS Accuracy - how much is actually needed
I think, as others have stated, that accuracy is entirely a non-issue. Another thought about having the sensor in the boat is reliability. Our VHF has an an internal GPS with an internal antenna and on occasions it will not be able to provide a position. I have never had this problem with any device with an external antenna.
Heading back to Lake Ontario for this summer. Relatively few stops along the way from Grenada. Martinique, Guadeloupe, St. Martin (must have something to do with the French food), then Bermuda, New England and up the Hudson/Erie Canal. We were going to go via Newfoundland and Labrador but June remembered that one of the kids is getting married this summer - details, details!