As I replied on a earlier thread I have used a hand held GPS designed for boats on a B-72. It worked well, but we did not use for area-nav. We used it as a backup for when ATC would give us a heading for a fix down the road. We looked up the Lat/Long and pluged it into the GPS. By the way the winds read out as current, current is 250 degrees at 95kts. That was funny, but it workred well.