I have the Garmin 176, which I think combines the best of handheld and fixed mount. It has the full maping capabilities and takes the Bluecharts, can be mounted and used with its built in ant. or a seperate ant. can be added. It is also battery operated (can be hardwired) and can be taken from boat to boat, or even in the car. It certainly is not as small as the true Hand helds, but it has a big screen for the maps.