Tom’s board spun out from under his feet as he attempted to surf the large wave. As he plunged backward into the roiling surf, he was frustrated once again by the lack of stability from his traditional Hawaiian-style surfboard.

A few days later as he was walking along the beach, he came across a wrecked and abandoned speedboat lying upside down. His eyes were drawn to the small metal keel on the bottom. He knew that keels were placed on boats to stabilize them during hard turns. He wondered what would happen if he put one on his surfboard. So, he pried the 12 in. × 4 in. keel off the boat, took it home, and attached it to his board.

As he paddled out to the waves, he noticed that his board didn’t move around as much. When he caught his first wave he was amazed, not only by the board’s increased stability, but also by an increased maneuverability. Before long, other surfers noticed his ability to stay up longer on the larger waves, and copied his idea. It was 1935, and Tom Blake’s fin revolutionized surfing.

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