With color mapping, a high sensitivity receiver and a built-in worldwide basemap, boaters and watersports enthusiasts will find the Garmin GPSMAP 78 to be a useful and reliable navigation aid. And don't worry if you drop it – it floats.

A worldwide basemap is stored on the unit's internal memory so you will always have an idea of where you are. The GPSMAP 78 interprets Wide Area Augmentation System (WAAS) signals so you can receive information from terrestrial antennas even when your view of the sky is obstructed. The WAAS system also provides greater position accuracy overall. Adding to the GPS technologies, this device also features HotFix satellite prediction which uses an algorithm to mimic the movement of the Earth. This technology allows the receiver to quickly regain satellite connection after a couple days of non-use, eliminating long initialization times.

Using the microSD card slot, optional additional map packages from Garmin can be added, including BlueChart g2 coastal charts and City Navigator NT. The unit is compatible with the BirdsEye Satellite Images subscription service and with Custom Maps, free Garmin software that transforms paper and electronic maps into downloadable maps for your device.

The 78 also supports paperless geocaching software, so you can transfer your data to your computer with the supplied USB cord or upload it onto the Web. The unit's screen displays key information, including location, terrain, cache difficulty rating, and hints and descriptions of hiding spots. All of this means no more manually entering coordinates and paper printouts for your geocaching hobby.

Molded rubber side grips allow for a firm hold even when wet, and the unit's IPX7 water-resistance rating signifies its ability to stand up to on-the-water use. The GPSMAP 78 is powered by two user-supplied AA batteries.