Yes, I think you're right that distro doesn't matter. As I've been reading through the responses, I realize that the two main issues are storage (don't want to use HDDs on a bounching boat, but SSDs are expensive per TB) and power (limited battery and variable voltage). As you say, corrosion may also been an issue that I hadn't considered. I'll probably have to check in with the sailing forums to see if people have trouble with their laptops corroding at sea. This server isn't likely to get splashed directly, but it will be exposed to a lot of humidity and variable temperatures.