Greg McDonagh pioneered the construction of boards in Australia from a foamed plastic core. He built first his own hollow marine ply board and was forced into the industry because there was no one to make the newer Malibu-type boards in Australia.
From a shed on the sand at Freshwater (Harbord) Beach, 6 feet tall, wide- shouldered, brown-haired McDonagh progressed to a factory in Brookvale supplying boards across Australia. McDonagh's designs are the results of extensive tests by leading surfers over the many years, constantly experimenting with boards and fin shapes.
McDonagh was one of the first to work on strengthening the early malibus, a joined balsa-wood plank, covered with a layer of fibreglass cloth.
He was also the co-founder (with his brother Denis) of the Surf Dive ’n Ski retail chain and always retained a keen interest in surfboard design and materials.