I got a gps in my boats. I still prefer the old fashioned navigation with a map, a compass and sextant. The gps is handy in fog and such but i dont trust the gps only. A few times i have seen that the map in the gps is more accurate and updated when it comes to how deep it is in sertain places so i make notes on my paper maps to update them with sertain details.
Got a gps in the car too but I have only needed it one time to find a place so if it had not been a gift i would not have gotten one.