I have a Magellan 315
handheld. It can mount in bracket in cockpit and can be powered directly from boats batteries if desired.
Think about where it will be mounted. If bulkhead might want something more permanent as the bracket for the
handheld can get in the way.
Here is my chief complaint with my unit that I would think about when buying in future: The buttons are not illuminated! The display is lit so works great at night but selecting a new waypoint or whatever is frustrating when you cannot see what buttons you are pressing!
On the plus side of
handhelds. You do not need to buy a new one everytime you buy a new boat! You can also take them when crusing, chartering, etc ...
Mike