A newly-deployed satellite has created the most-detailed map yet of the ocean floor, finding hundreds of hills and underwater volcanoes that were previously missed.

With the help of a powerful satellite called SWOT ... used the data to create a hyper-detailed, high-resolution map of the ocean floor. In fact, it's twice the resolution of previous ocean ...

The best GPS units offer reliable ... including topographical and off-road-specific maps, the ability to mark customizable routes and waypoints, and access to satellite communication features ...