Popular Multi-Use Garmin Gps units for fishing and on the water activity. A portable Multi-Use gps unit provides you more than one use for your navigation needs, this feature adds value to its use and because it is used for several activities it is friendly to learn. Here is a list of our current top 4 Multi-Use units for Water and Fishing. This is just a few of the Multi-Use units we have in stock for use on water and other activities.