Thank you

Hey Guys, I'm fairly new to hammer mapping and I was having a problem when trying to make a surf map. The problem is the visibility is very short in my map(meaning you can't see very far). I de-compiled surf_ski_2 and from getting the measurements from that map I should be able to see farther but I can't. Am I doing something wrong by making my outside walls brushes sky or is it just some super secret that I need to know?

(Sorry, in advance if this is a stupid question)
(EDIT: Also forgot to mention I'm using Hammer 3.4, CS Expert FGD, and ZHLT 3.4)

Thanks guys!
Tiffany XOXOXOXOXOXOXO