THANKS! For the replies; I'll summarize some of this over in the
BoatDesign.net discussion.

- Salt air, Humidity - Plans now are 12 watt system board in
sealed/gasketed aluminum box. Anti-corrosion insert, humidity control
insert. Heat transfer to 2 square feet or so of box surface to cabin
air. Need a maximum inside-cabin temperature to do the numbers.

- The 2.2 Gb and 3088 files is great data.. thanks! This fits with my
experience, no problem for 60 Gb 1.8" notebook type drive using 1
watt.