While sailing on the Long Island Sound, inventor and sailor Paul A. Sperry slipped on the deck of his boat and fell overboard. He was able to pull himself back on board, but the experience drove him to develop a non-slip shoe. While experimenting with possibilities for non-slip shoes, he noticed his dogs’ ability to run down the icy hill without slipping. The grooves on the paws of his cocker spaniel, Prince, inspired him to try cutting grooved patterns (siping) into a natural rubber sole. The pattern of grooves or cracks on his dog's paws gave him the idea for a canvas upper-shoe with a herringbone pattern of grooves on the sole.