Waypoint
Freeware for downloading and uploading waypoints, routes and tracks to Garmin GPS.
Buzzards Bay Waypoint Data
A local compilation of waypoints for Narraganset and Buzzard Bays.
Joe Mahaffey's GPS Reference Site
Excellent source of GPS information and links to other resources.
U.S. Coast Guard Navigation Center
The Coast Guard's navigation center with authoritative data on GPS and other navigation systems.