Online Only, Do Not Call - Your aquatic adventure's waiting, so map out every last stop or just wing it with the Garmin echoMAP 53cv GPS Map and Fishfinder Combo. As you're scouting for your next big catch, you'll get some of the best views on the water with the built-in ClearVu scanning sonar. And between the LakeVü HD maps and constantly updating GPS, you'll always have an accurate read on your location.
The easiest way to think of the difference between a marine GPS unit and a fishfinder is what information each provides. The marine GPS shows the location of the vessel on the surface of the water, while the fishfinder shows objects and fish that are between the bottom of the boat and the floor of the body of water that the vessel is located on. Both units have many different features that the boater or fisherman should research to determine what the best features are that can fit into his or her budget. If the budget allows, a combination GPS/fishfinder unit can be useful and provide for a sleeker instrumentation panel. Finally, eBay is a terrific place to find these units and evaluate features, because of the large variety and selection.