Vessel 1 was traveling along the shoreline by Craig key. Vessel 2 came along in close quarters to vessel 1. Vessel 1 slowed down but was unable to get away from V2. V2 struck V1. V2 did not have FL#'s displayed so V1 was unable to get any FL numbers. V1 thought that everything was fine until a day later he discovered that the fuel tank was leaking. He took the boat in for repair and called FWC.