A full version maps & gps app for Android, by MarineTraffic

MarineTraffic provides global ship and yacht positions that are almost real-time. The app covers the majority of significant ports and shipping lanes because it is linked to the biggest network of land-based AIS receivers. You may search for ships, boats, and seaports, examine watercraft on the live map, and discover what’s nearby. Additionally, it enables you to see both 48-hour and current wind forecasts on the map. 

You can also use satellite tracking to locate and identify ships that are traveling outside the range of AIS receiving stations that are located on land, as well as the Augmented Reality tool to locate ships. To find out everything you need to know about the ships nearby, all you need to do is point your camera toward the horizon.