Seawater Grounding for High-Frequency Radios

May 10, 2004
Hunter 340 Bremerton, WA up from Woodland
Agree with all above. Brian, my first iteration was 1' length of copper pipe. It worked well, but corroded in hours and I didn't trust Cu oxide for contact, so changed to bronze. A short bronze rod or pipe might work if you can find one. Another idea worth trying would be to just trail a couple feet of tinned braid (short enough to not reach the prop in reverse!) . Interestingly, my tinned braid dropper is green where it is above the waterline, but still pretty un-corroded where it is under water when used.
What I am going to try this winter is to hook my braid from the nearby thru-hull through a relay to the tuner ground lug, then energize the relay with the switched 12V to the tuner. That way, when the radio/tuner are off, there is no DC galvanic path to the thru-hull. I think I like this better than the conventional blocking Capacitor coupling method. The thru-hull I use is on the centerline and less than a foot under water.