North Shore
Summer (roughly May–October) is usually flat enough to swim at Waimea Bay; in the winter surf season (November–April, peaking in December) these are big-wave breaks and Ocean Safety tells everyone to stay out of the water. On big days watch from the sand well above the high-water line — sets wash far up the beach — or from the highway pull-out above Waimea Bay. Contests (Pipe Masters, the Eddie) run on holding periods called at short notice and bring heavy traffic on the two-lane road.
Free, no booking. Start in Haleʻiwa and drive north-east on Kamehameha Hwy (Route 83): Waimea Bay Beach Park, then ʻEhukai Beach Park (Banzai Pipeline), then Sunset Beach, all within about 6 miles. Parking lots are small and fill early, especially on weekends and swell days — arrive before 10 a.m.; about an hour's drive from Waikīkī outside rush hour.