Mounting a flap on a Nidelv 26 can do a lot for the the speed and economics of the boat. In this video we show how its done with a flap from Asdal Trading in Norway. This is the closest you can get to a original modification. The flap will (depending on engine) 1-2 knots on the topspeed. However the interesting part is more the ability to keep a nice cruising speed at lower rpm and thereby also save fuel. We use West System for this type of work.