American designer based in the Detroit, Great Lakes area. He is best known for 'Flying Buffalo', a breakthrough design in the 1960's. DeClercq did tests for this design by towing small scale models behind an outboard motor boat on Conner Creek in Detroit. The 36' 'Flying Buffalo', which Declercq also owned, won the Bayview Mackinac in 1964, 1967, and 1968, the Chicago Mackinac overall in 1966 and 1967, and the Mills overall in 1966, 1967, and 1968. Cheoy Lee eventually bought the design. They sold it as the Offshore 36 of which more than 1100 were built. (not confirmed)
Another creation was 'Spirit of Michigan', a tandem centerboarder for the Canada's Cup match racing series of 1972. Declercq was also holder of several patents including one for a self tailing winch.