Check out this time lapse of the Pillar Point Harbor in Half Moon Bay. Notice the abrupt up and down motion of the boats. A tsunami is not just one wave. It's a packet of waves that can last for several hours. This rapid surging of water can create dangerous currents.#tsunami pic.twitter.com/qu5joaFgLG

— NWS Bay Area 🌉 (@NWSBayArea) July 30, 2025