Quote Originally Posted by G H Z View Post
If you need it to be fairly immune to water yet still breath I'd consider some form of conformal coating on the board.
How about this stuff?

TechSpray's
Fine-L-Kote SR
Silicone Conformal Coating Spray

Recommended for harsh environments, Fine-L-Kote™ SR has excellent moisture and fungus resistance and allows for vibration, movement and rapid changes in temperature. Contains Opti/Scan™ black light indicator for inspection purposes. Non-ozone depleting.

Product Information
MSDS Sheet