I have two GPS units, one of which is being borrowed by my daughter; the other is a Garmin Etrex Legend that I keep for immediate access to waypoints, boat’s heading and speed. My other GPS is a Lowrance Expedition c model that has colour charts that I use for pilotage. The older and cheaper of the two GPS units is the Etrex; I initially mounted it at the aft end of the keel box, but I could not see the display clearly there, and when I was using my cockpit spray cover I could not see it at all.
To improve the situation I have made a bracket for the GPS near the front of the cockpit on the starboard hand side where it will not get in the way of the sail when it is stowed. In that position the unit is a little more vulnerable than in the cockpit, but I think the advantages will outweigh the disadvantages. At least, that is what I believe. I’ll have to give it a go when working the boat to discover if it works okay.
Confessions of an Old Salt (Has more details of the two GPS Units)