Extensive links to technical FAQs, articles, and other resources on the National Marine Electronics Association's standards for data communication among boating instruments (GPS to Autopilot, for instance).
Unmoderated forum on marine electrical and electronic equipment. Good advice and resources here, but you have to dig and you have to be selective.
For the skipper who has everything - but needs more data. BMW and TAG Heuer have developed sunglasses with a heads-up display of your sailboat performance data. Not commercially available yet.
A discussion board and photo gallery for cruising sailors and wannabes focused on sailing instruments and communications equipment. Autopilot, radar, sonar, chart plotters, satellite telephones, mobile telephones, internet, marine e-mail, VHF, HF, SSB, etc.
Carefully calibrating your instruments and checking for consistency let you take advantage of a velocity prediction program to find the fastest course upwind and downwind. Tells you how to find a VPP for your boat.