The meaning of "do a full-pipe roughie"

(Partial/tentative answer) I would guess based on the context that it refers to some skateboarding stunt, but I can't find any other examples of the exact phrase "full pipe roughie" being used or defined.

My guess is based on the following evidence:

• According to the "Under the Dome Wiki", Ben Drake "was a fanatic fan of skateboarding". Michael's answer confirms that this is also part of his character in the original novel.

• Ben is apparently a teenager, and some kind of skateboarding stunt seems plausible as the highlight of a teenager's life (up until the romantic experience mentioned in the quote).

• "full pipe" is a term that comes up fairly often in reference to skateboarding. E.g. you can see it used in the title of the Youtube video "Full Pipe Skate", which also demonstrates why it might be considered an accomplishment to stay "vertical" (approximately) while doing some stunt involving a full pipe.

I'd guess 'staying vertical while doing a full-pipe roughie' means

staying upright while surfing a wave that has formed a 'full-pipe' around the surfer

a 'roughie' being a rough wave / sketchy ride.

To expand upon sumelic's excellent answer, it is certainly implied to be a skateboarding trick.

From the novel:

The kid was Benny Drake, fourteen, and a Razor. The Razors were a small but dedicated skateboarding club, frowned on by the local constabulary but not actually outlawed

Source

Norrie is also a member.

It would appear that there's no such trick in real life, so it's either a trick they've invented or a name they've given to an existing trick. I suppose it doesn't really matter.

It has nothing to do with surfing. It is supposed to be a skateboarding reference but it’s not a real one. King either did no research on the actual names of skate tricks or, as someone said above, invented new ones on purpose. He’s a great storyteller, but his weakest writing comes when he tries to write dialogue for kids or subcultures he has no understanding of. This is not uncommon. Don Winslow’s two surf centered crime novels are unreadable to me, a surfer of thirty years, because he gets everything so horribly wrong about it.