Hi Bobbie, I don't do heavy duty navigation any more, and if the fog gets real thick, I "think" I can still find any one of the shores of the lake where I sail. However, I find a GPS is a very nice knot meter. It give me an instant readout of sailing speed and the effects of sail / sheet tweaking. My Garmin also tells me the altitude of the lake, and when we go to Lake Champlain, I then have that altitude as well. Just sailing at sea level removes half the fun! It's a nice toy that only cost a few Boat Dollars. A friend of mine measures toy purchase costs in Martinis. It's only a two Martini tool. Had to buy it! Connie