Not wishing to get into a debate but accuracy of today’s GPS and the ability of the user are directional proportional. On water, where reception is typically excellent, you can consistently get 3 meter accuracy.
Before Selective Availability was removed I used a Differential Correction Receiver in conjunction with my GPS. This service was offered by a company out of California and was piggybacked on top of KZ106’s FM signal. I could get 3 meter accuracy with this service. When SA was removed you didn’t need differential corrections to accomplish this and these companies went out of business.
With WAAS, which was designed for air craft, accuracy is enhanced but the further you are from the land based stations, that figure error correction from a known position and transmit them to the WAAS satellites, the greater possibility for errors exist. In some cases your GPS would be more accurate by disabling WAAS. Even then accuracy should still typically be in the 10 meter range.
I trust my GPS. On Weiss Lake, a very dangerous lake, using contour map cards, I can run the channels without using a depth finder. Now I haven’t tried this but would not hesitate to do so after seeing how accurate these GPS/maps are.
As for the discussion about Navionics Map cards, versus Fishing Hot Spots Elite, I like the HotSpots Elite better. The Navionics cards will reduce your zoom range from .02 to 1/8 mile in Lowrance units. This has an effect on Map accuracy because contour lines are closer together, especially the enhanced maps with one foot contours. A lot of ditches, as example on Chickamauga Lake, do not show up on these maps. I demonstrated the difference in the two maps to Andy Morgan and Luke Clausen while doing some GPS work for Andy. All the map cards are good, some are better than others IMHO.
