The US Geological Survey (USGS) and their associates produce Topographical maps, which are compatible with NavPak.
[ Go to USGS DRG page ]
The US Naval Observatory, Celestial Navigation Resources
[ Go to US Naval Observatory ]
National Geospatial Intelligence Agency (US). Maritime safety Information. Online American Practical Navigator, Notice to Mariners,and other useful info.
[ Go to NGA ]
Boat Owner's World. Big list of boating related links.
[ Go to BOW ]
Boating links. Another big list of boating related links.
[ Go to Boating Links ]
Discovery Sailing. CYA and RYA courses, plus RYA Yachtmaster examiner.
[ Go to Discovery Sailing ]
Cool solar system and astronomy apps for Android and iOS on Free Apps for Me:
[ Go to Astronomy apps ]