Here's another useful app for sailors with iPhone or Android phones or devices with connectivity in coastal areas. Ship Finder presents a scalable map view of your current area (which can be scrolled to other areas as well) that shows the location of ships sending AIS data, as is required of most commercial shipping and passenger vessels. If you're in fog or see a ship's lights at night but can't determine its heading, check Ship Finder. The free version (as in the iPhone photo here of four ships in eastern Long Island Sound) shows a ship's location and the direction in which it is moving. The paid version of the app provides additional information about the ship, its route and destination, and so on. While the app also allows you to share your sightings with others via Facebook and Twitter, I have difficulty imagining why anyone other than committed "train spotter" types would do that. Still, this is another valuable navigational aid to add to sailors' tech toolbox along with chartplotter and tide apps.