Bonzer is a variety of surfboards with either 2 or 4 long keel fins that have a lot of cant and toe in and a large back fin. They have significant double concaves running through the fins, these create a venturi effect that accelerates the water out through the fins and off the tail. These boards have tremendous holding power and can generate blazing speeds which are otherwise only obtainable by the best surfers in the world. The design was created by the Campbell brothers, the name was from an austrailian slang term bonzer meaning "bitchin'" or awesome. the 5 fin variety is looser and snappier than the 3 fin variety.