This may sound stupid, but I honestly don't know the answer. I'm a V-drive guy, have been for forty years. A Stevens 18 ft Silhouette with a built 509 CID nasty BBC. I've been looking at boat ads just for fun and see quite a few V-drive boats that look like flat bottoms. Some say flat bottom and others say runner bottom. Until last year I never heard the term runner bottom. Are they the same thing?