He sketched the design for his famous 1957 wave house with a grease pencil on top of his surfboard while trying to get to the "soul of the site" (aka surfing late when he should have been working). The "wave house" inspired the Danish architect Jorn Utzon, who went on to design the Sydney Opera House.
Harry Gesner is over 80, still works & still surfs (with a seagull feather encrusted Gath Helmet).
Below the sketch of the Tahitian bachelor pad, Gesner designed for Marlon Brando. He created a natural air conditioner out of a 25 ft long aquarium that pumped cool water in from a reef outside the house.