How hard did you fall? Did you trip or get wrecked on the skateboard? Reason I ask is because I too broke my scaphoid a few years amongst other bones in my wrist (got dealt on my snowboard). My surgeon gave me the low down on this little f'er. If it doesn't heal correctly you'll be sure to have arthritis pretty bad in that hand when you get older. Blood flows through it somehow or another and if it's broken, obviously blood flow is inhibited and the bone will begin to decay. Mine was in half so they put a screw through it and I haven't had a problem with it since.....catch up with me in 30 years and I may be telling you otherwise
Go to the DR, dude. Deny the cast if you really have to but I would give it the proper attention when you get back. Until then, highly doubt any brace is going to really help you out unfortunately. <Debbie Downer>