There are no spares at bowling ball beach. You can only experience these round, smooth geological wonders at low tide, the so-called bowling balls are actually known as a "concretion", sedimentary rock formed by a natural process. These boulders are the result of millions of years of concretion and erosion. Located at the northern end of Schooner Gulch State Beach and hidden away off of Highway 1, I parked my Jucy campervan, followed the path on the ridge and then scrambled down a small path to the beach to find them! Make sure you check the tide schedule first before making the trip!