I'm a marine biologist and was really in need of something like this. I use this pack for everything. The "wet" compartment is big enough to hold my board shorts, rash guard, booties (not much room to spare, though) and does a good job of keeping the main compartment dry. I'm not much of a skateboarder, but the straps along the back designed for holding one are perfect for securing my fins when I come out of the field.
When I'm not sopping wet, this is my academic pack. I usually carry two computers- a 16" vaio and a little Eee netbook. The laptop compartment is big enough to hold both at once and I can easily fit a few textbooks and files with them.
The straps are comfortable and quality is on par with what I expect from Patagonia.
One complaint though: the computer compartment can be a bit tough to access if you have a larger computer and a full pack. The main zipper doesn't extend down as far as I would like, but this is pretty trivial in comparison to all the good things about it.