Let’s say one person weighs 150lb and rides a 6’2" x 18.25" x 2.25" standard shortboard. If a 200lb person wants to make scale up these dimensions to make a board for himself, should he try for the same displacement volume per pound, in which case he might make a 6’6" x 19.75" x 2 5/8" or does he need the same amount of planing surface per pound, in which case he might make a much bigger board, maybe about a 7’2" x 21" outline?