Computer Designed for boats - interest?

[Doghouse]

I have been toying around with the idea of building a computer designed for the use on boats. The design points being water resistant, low power consumption, and low cost.

This is not an off the shelf solution, I would be custom designing them, and wanted to get a little input on some of my ideas, and find out if there is interest in purchasing such a computer.

1. able to use pcmcia cellular cards
2. able to be hooked up to TV or DVI.
3. built in? or external GPS
4. user expandable with off the shelf parts.

So what do you think?