Garmin is probably the largest manufacturer of GPS navigation. Garmin makes GPS units for all outdoor activities from automotive, marine, fitness, and hiking. The Garmin GPSMAP line of chartplotters and fishfinders are the industry standard for this category. Garmin has also introduced in recent years their echoMAP line of chartplotter/fishfinders that are good for inland lakes, rivers, and more recreational saltwater cruising. Garmin also offers many other products including marine VHF and marine instrumentation.