Quote Originally Posted by Slab Junkie View Post
Chart speed should be the same or a tad bit higher than your GPS speed, i.e. if you are running the boat at 3.5 mph set your chart speed at 4.
+2...Majority of the time I have mine set at 4 because I like to graph at about 3.5-3.9 mph. Whatever your ground speed is, round up to get your setting, or at least a real good starting point. This is one case where faster is not better - I had to learn the hard way

-T9