If that bag doesn't work out for you Chris, check out the Booq bags (All Products by booq, laptop backpacks, laptop bags, iPad bags, sleeves, briefs
). I bought a Booq bag 8 years ago to carry my work computer and gear in. I have used it EXTENSIVELY (almost every single day) for those 8 years and it is just now starting to show wear on one seam. The current bags are made of 1680D Ballistic Nylon exterior and 420D ripstop polyester linings.
If it does work out for you, keep us posted on it's performance and carrying capability...oh, and keep us posted on your trip to the beach.