GPS

[DetectorGuy]

I use a Lowrance H20c and I really like it but I see now that it is discontinued. I have a Lakemaster chip in it that has something like 750 lakes in it that have 3' contours mapped out, and about 200 lakes with 1' contours mapped out. Most of the 10,000 (actually closer to 15,000) lakes in Minnesota are not contour mapped yet on the Lakemaster chip. Every year they add more contour mapped lakes. The Western 1/3 of Lake Superior is mapped in 3' contours I think. As far as accuracy... I think its as tight as any non military GPS units on the market. The trick with any of these is that they will be more accurate on Coordinates that you locked into rather than taking coords from someone else's GPS unit. The reason is that each GPS should be synchronized periodically to survey stakes near where you are using it to lock the Global Positioning Satelites to the general area you are in. These markers (survey stakes) are all over but often overlooked. Using Coords from one GPS on another GPS could put you off 15 feet easily. I like to think that I can get on the same 5' circle every time with mine.

Couple the hand held GPS with Google Earth and the coordinate generating capability that program has and you have a world class navigation system. I have overlaid contour maps from the MN DNR "Lakefinder" site on top of Google Earth images, used the curser to place virtual push pins on proposed depths (say the 15' deep contour line which is usually the weedline) at a spacing of 300' apart and each virtual push pin was a dive site with a coordinate that I could punch in the hand held GPS. No overlap (unless you wanted one) and no missed spots (again unless you wanted one).

My wife is the Vice President of Northern Pines Mounted Search & Rescue and they search for missing people on horseback throughout Western Wisconsin. I taught them what I knew about using hand held GPS for ground searches, and what they could and could not do with a GPS. Its really not too hard to figure them out, just use it a lot and find out what it does.