Let's assume that I seriously would like to be able to use my computer as easily and as carefreely while on a boat as I do while at home. In short, if I were on a boat for extended periods, such as two weeks at a time and occasionally over a few days out of port (this would be a 2 person sailing vessel), what would my options be for power, durability, and of course, internet access? I want more than just email, as I will likely keep doing a tad of development, and will be looking at google earth from time to time.

I am already assuming that we're going with some kind of laptop, maybe even a macbook pro 12". I personally feel that netbooks are underpowered. And the last computer that I got a boat-friendly rating for was a ZX Spectrum, which was before the internet, and was likely due to it's 12vdc-happiness.