Pelican - make sure it's REALLY waterproof
There 1st gen cases were not. I know - I warrantied it when I could blow air through it.
Very good against shock but . . . it's better to have a machine with no moving parts and a robust frame . . . the MacBook Air is cheap, small and stupid robust.
I had one in a soft case on the back of my KTM for 12,000 miles and regularly ripped across the Mongolian steppe among other places at 140kph.
This note is being typed on that machine.
No problems at all.
This year I'll use an iPad with a Touchfire keyboard. Under 1 pound, 9 hours of battery life and photos, blog, etc easily updated.
Orange, it's the new black.