As a fishman, his physical strength is ten times that of a normal human and double that under water. Although seeing as he is the captain of pirate crew of Fishmen and a rival of Arlong, he could be assumed to be stronger than the average fishman.
He was last seen about to battle with Gasparde and his crew. The outcome was never seen, but since there was no damage on Gasparde's ship, it could be assumed that Willy and his group pirates were defeated by Gasparde's pirate crew. He realized that Gasparde had rigged the race when he saw the former marine sail away from the main course.