Consumer GPS receivers come preloaded with digital maps, or "basemaps" and often come preloaded with additional, region-specific maps to make them fully functional and useful out of the box. But there's no reason to stop there. Every class of GPS device has an extensive library of supplemental maps that can make vast amounts of additional information available to you, or meet specialized needs.
1. In Your Car
In-car GPS units can be enhanced with city-specific guides. Additional countries or continents may be added, as well. Premium automotive maps may include additional detail on restaurants, lodging, attractions, entertainment, shopping, emergency services, ATMs, and gas stations. Supplemental automotive maps sell for $99 - $140.2. On the Trail
Handheld GPS units often include good topographic maps, but maps with outstanding levels of detail, additional information, and better graphics may often be added. Some maps add specialized themes, such as national parks of the eastern U.S. Organizations such as National Geographic offer specialized maps. Supplemental maps for outdoor recreation may include campgrounds, fishing, recreation areas, trails, river recreation and more. Additional maps for this category sell for $49 - $120.3. On the Golf Course
If you golf, your favorite courses are probably already mapped out to the foot by a golf GPS provider such as iGolf or SkyCaddie.4. On the Water
The specialized nature of marine navigation has spawned a robust market for charts. Supplemental data may include aerial views of marinas, 3D renderings of shore topography, fishing charts, regional lake and coastal maps, and even simulated underwater views.5. In the Air
Aviation databases are most often updated online, and include Jeppesen (a subsidiary of Boeing that issues official charts), obstacle, and terrain databases.
