J. Hillier of Sausalito, California, asks:
"I bought what I thought was a waterproof handheld VHF radio, but when I dropped it in some water in the bottom of my inflatable it died. It was only in the water for a few seconds before I picked it up, and even though it did work for about two hours it went dead after that. What do those specifications really mean?"
Gordon West replies:
Handheld VHF radios have a number of categories of water resistance but the most common are splash-resistant, watertight, and submersible. Usually you’ll find the description on the front of the unit. A splash-resistant handheld is the most vulnerable to water and can survive just that; a splash from any direction. It’s best to protect these units by putting them in a polyurethane waterproof pouch; the pouch will also keep help the radio afloat should it go overboard. All devices will also have either a Japanese Industry Standard (JIS) rating or an International European Community specification that defines the level of water ingress protection built into each product. Visit hy-com.com/jis.htm. for descriptions of these. If I were carrying a handheld in an inflatable, I’d probably want a unit rated at least JIS 6, which is watertight.
In your case, I suspect that though the radio’s innards were still dry, enough seawater got into the battery compartment to corrode the contact pins and knock out the unit. Always take the battery out of a radio immediately after if it gets wet, clean the battery compartment and contact pins with a cloth dampened with freshwater and alcohol, then let the unit dry completely. Clean and recharge the battery, then reinstall it in the dry compartment.
Units having the highest JIS ratings (JIS 7 and JIS 8) can be immersed for a specified period of time and still work. However, these radios should also have their battery and battery compartment cleaned and dried if they get wet. If the display begins to show some fogging, let the unit dry in the sun. Chances are good the fogging will disappear after it warms up.