Robby is regarded as the greatest windsurfer of all time. When he retired in the mid-1990s he had won a total of 24 world titles.  

The best-known name in the sport, he has played an important part in its development. Over the years, he has helped in the evolution of the short board, the window in the sail, foot straps and the harness. He has also written two books on the sport while his three windsurfing videos are regarded as classics.  

Robby, who began surfing and sailing in his early years and then started windsurfing at the age of 11, won his first world title in the Bahamas to become the youngest world title-holder in the history of the sport. He successfully defended his crown the following year in Sardinia and made it a hat-trick of world titles when he triumphed again in Cancun in 1978 and in Florida in 1979.

For the following decade, he dominated windsurfing competitions worldwide, travelling extensively and competing in more than 20 countries each year.

An excellent slalom and course racer, his Hawaiian upbringing from the age of five has provided him with a special affinity and talent for wave riding. He made a clean sweep of all four titles in the inaugural Pro World Tour in 1983, clinching the overall, the wave riding, the slalom and course racing, a feat which he repeated in 1984.

Although his windsurfing dominance was waning by the early 1990s, he was still good enough to finish second in the Pro World Tour’s overall championship in both 1994 and 1995. In total he claimed 150 event victories in his career. 

At the end of his competitive windsurfing career, he switched his attention to kiteboarding, a discipline in which he won the slalom world title in 1998. The following year, he won world titles in both slalom and jumping.

His great passion is riding big waves and he can often be found performing high-level manoeuvres at one of the famed hot spots off Ho'okipa Beach in Maui. He is renowned for his powerful charges through the water with a technique that no board sailor can match.

He became chairman of the Professional Board Sailors’ Association from its inception in 1987 until he chose to retire from the position in 1992.