In the conditions you describe (which precludes salt water
actually getting into them) in my experience the things should do as well as if they were on shore.
Actually with a couple of things I've been wishing for years that they would die so I'd have an iron clad excuse to replace them but they won't - TV and automobile type radio/player/speakers have been on board for heading towards 13 years with no sign of any damage or problem (so TV is old CRT and player won't play MP3's
anything failing and that includes electronic clocks, amateur transceiver and linear amplifier which spent maybe 6 years on board and are still like new inside and out, inverter
. Has been a cellular terminal on board for many years and just an el cheapo phone
plugged into that and no problems, vacuum cleaner, kitchen mixer, electric
heaters, power tools, etc all come to mind but no particular problem.
We make a habit of not buying
stuff that is plainly junk or of non proven brand though and also run everything frequently.
On bigger boats we put domestic stereo equipment
, front opening ss case refrigerators and freezers, TV's, etc, etc operating in the tropics with no problems - although boat is bigger, is same sea air but maybe less chance of direct contact with seawater (well except for one that took some front windows out diving
into a big steep sea
). People sometimes seem concerned about notebooks and bumpy rides but they go fine on fast power boats slamming along at 40 knots with no problems either.
I see plain mild steel
baked enamel (or whatever is used for coating them) chest freezers, refrigerators and washing
machines on old fishing
boats which seem to keep operating electrically even though they are in wet salty environments and the mild steel is corroding away. Even see domestic chest type freezers on the decks of fishing
boats operating seemingly happily, but that obviously not a recommendation
But emphasise all bets are off for those that have salty wet boats