Ask Sail: Water Getting into Coax


Q: While inspecting behind the nav station for my spring cleaning, I discovered water behind my chartplotter and VHF radio stack. Freshwater to boot! Do electronics leak? I didn’t think so. — Everette Gracy, Norton Shores, MI

Gordan West Replies 

Last winter your region was pounded with rain, ice and snow, right? With a masthead VHF antenna or a stern-pulpit GPS antenna, water from rain, snow and ice can creep down coax cable via an exposed antenna connector jacket or seep into the jacket through cracks in, say, a GPS sensor coaxial cable line that froze last January. The water then migrates via capillary action down the braid of the coax, eventually pooling at the connector that feeds your antenna connections. The good news is that the water likely won’t get into to your electronics. However, you will soon be off the air with the affected coax line, as water in the coax braid ultimately eats up the copper shielding. Time for a cable replacement. The problem won’t cure itself.

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