A Royak is a sit-on-top Kayak (as it is called today) that integrates the features of a surf board with a kayak, and has revolutionized paddlesports. It was invented by Roy Grabenauer in 1968 after years of experimenting with a variety of designs and innovative technologies, although Tim Niemier is celebrated as having popularized the craft with the rotomold process.

Roy needed a boat that would not sink, and that he could get in and out of easily in rough water. He wanted a craft with enough storage for his gear that was also easy to maneuver, lightweight and comfortable. He and his wife were using everything from innertubes to surfboards as their platform, until his wife developed back problems and the search for an alternative became imperative for them to continue to enjoy their sport.

Roy worked as a chief electrical engineer for the Sacramento DMV and began experimenting with a boat fabricated from an airplane wing tank. The result was a torpedo-shaped craft that, to quote an article in National Fisherman from April, 1978 "...resembles a topless kayak going backwards."