Based on the provided text, some key features of the Garmin EchoMap 55dv are:

1. Compatibility with microSD cards: This allows users to easily access and share maps between compatible devices.

2. Quickdraw Contours feature:

- Creates personalized fishing maps with 1-foot contours.

- Provides detailed imagery of fish and structures beneath the surface of the water, helping in discrimination among targets for a clearer view of the underwater environment.

3. CHIRP sonar technology: This feature provides clear and detailed information about what lies beneath the surface of the water.

4. Built-in GPS and GLONASS satellite reception:

- Offers fast and accurate positioning.

- The high-sensitivity internal GPS antenna quickly locates your position, even in challenging environments.

5. 5-inch color display with a resolution of 480 x 480 pixels: This provides clear and easy-to-read maps and information to users.

In summary, the Garmin EchoMap 55dv is designed as an advanced navigation tool for boaters that offers reliable and accurate assistance while on the water.

Garmin quickdraw file format