Slippery Soles

Late one night on Long Island Sound, Paul Sperry slipped and fell from the deck of the Sirocco. Everyone was fast asleep, but he was fortunate enough to grab hold of some rigging and somehow clambered back on board. Years later, when he was asked what motivated him to create the non-slip boat shoe, he responded succinctly, ‘Because I fell overboard, that’s why!’

At that time, boating footwear consisted of either canvas uppers with a slab of crepe rubber glued to the bottom or shoes with coiled ‘rope’ soles. Crepe was the preferable material, but it was slippery when the deck was wet, whereas the rope sole would slip when it was bone dry. Sailing barefoot was not an option, as those foolhardy enough to try it regularly broke their toes.

Once the sailing season came to its conclusion, Paul Sperry was a man on a mission. Through the winter of 1935, he spent hour after hour in a makeshift workshop at his New Haven home, experimenting with rubber combinations as he searched for an elegant solution to slippery soles. One freezing cold day, he pulled himself away from his work to clear his head, stepping out into the snow with his Cocker Spaniel, Prince. Paul watched the dog run across the frozen landscape with ease and he began to wonder how Prince was able to stay upright so easily. His first thought was that the dog’s claws must be digging into the snow like a track-runner’s spikes, but as Prince turned and ran towards him, he realised this wasn’t the case. Inspecting the dog carefully, the curious inventor observed something that would change his life forever. Paul Sperry had an idea.

Racing back to his workshop, Paul took out a chunk of gum rubber a quarter of an inch thick. Using a razor sharp blade, he proceeded to make parallel cuts in the rubber material a fraction of an inch apart, almost all the way through. When that was pressed against a wet piece of polished metal – with the pressure applied at right angles to the cuts – the traction was dramatically increased. So far, so good. But when he applied pressure in the same direction as the cuts, the rubber became slippery. Paul quickly realised that cutting the rubber in a zig-zag herringbone pattern – known today as ‘siping’ – was the perfect solution he had been looking for. He glued some hand-cut rubber to the base of an old pair of shoes and the first Sperry Top-Sider prototype was complete.