J.H. Hagedoorn – inventing the Hapa: A review of a geophysicist's ‘other’ work and how it inspired others



This paper describes J.G. Hagedoorn's work on ‘ultimate sailing’– the combination of a manned kite and a water kite called a Hapa, constituting a minimal sailing system – and the way others have taken up his challenge to sail while suspended from a kite. Hagedoorn's goal has not been entirely achieved, but ‘near’ and partial solutions have been reached. Kite-Hapa-sailing continues to pose a ‘Holy Grail’ type challenge to many kite-sailors.