I'd be more concerned about salt damage.
I worked in the Hamptons and saw firsthand how the ocean would necessitate yearly repairs and maintenance.
+1 to the dehumidifier.
In particular, avoid high-air flow components that use bare boards without solder mask.Anything with a tube, and amplifiers fit into this category.A solder mask is a colored layer added on top of the copper/tinned parts to help reduce solder overflow and reduce corrosion. Think of it as a board insulator. Silk screen is applied on top of it to identify parts.
Some companies like Audio Research, commonly use bare boards without the solder mask but I read ages ago you can request solder masked circuits, which are much more resistant to humidity and salt air.Luxman is another company that in the premium parts uses bare, unmasked boards. They give it a fancy name like rubbed boards or something. Hogwash, but same idea.
The bare boards are usually pale yellow, and traces (not just pads) are tinned and appear silvery. Masked boards are of many colors, typically dark green, blue and red are used too. Traces are not directly visible because of the mask.
This issue is not nearly as bad in sealed components, like a DVD player, or solid state preamp that has no ventilation holes.