GPS has been a boon to recreational and commercial boaters. Moving-map displays and navigation overlays are incredibly convenient, easy to use, and dramatically enhance all-weather, all-light-condition safety. The ability to provide precise position information in case of an emergency is another key safety feature. Built-to-purpose, portable chartplotters often come loaded with detailed coastal maps, and many additional maps for the earth's oceans and lakes are available.

Marine portable features include:

• Bright, color, moving-map display
• Navigate to point
• Navigate route
• Navigate saved track
• Man overboard emergency waypoint button
• Speed, distance, course
• Digital compass
• Satellite images
• Auto guidance
• Tide station information
• Fishing charts
• Customized alarms

Portable marine units range in price from $350 to $4,000.