I second the comment for Chartwell Surveyor's notebooks. They are the dog's danglies when it comes to weatherproof books. They do either horizontal or vertical opening. The outer cover may not be plush like Moleskine or Rhodia, but they are built to last, and I'd say price wise are cheaper than those two. Fantastic.
Having said that, they are, I think, a UK brand too.
Failing that, the Rhodia notebooks are really good . I use one for my photography notes, and with a fountain pen, especially nice to write on.