Unmoderated forum on marine electrical and electronic equipment. Good advice and resources here, but you have to dig and you have to be selective.
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.
This sonar looks both down and ahead. Information displayed is not historical, as is the case with all digital sounders, but is in real time.
This depthsounder can be a standalone unit, combined with a log, or integrated with other navigation instruments via an NMEA interface.
Depthsounder digital LCD instruments that also monitor air and water temperature.