by Peter Saltamachio
What used to be a well-kept San Diego secret has become the most feared beach break in the county. Black’s Beach rests just a half-mile up the coast from the mellow waters of La Jolla Shores, where swimmers of all ages can enjoy the small waves and warm sun. During strong swells, Black’s Beach can see ten-to-twelve foot barrels while La Jolla Shores sees waves of little more than two feet. Why is there such a disparity in wave height? The answer lies beneath the waves.
The La Jolla and Scripps Submarine Canyons connect the shore with the San Diego Trough, an undersea fault zone. Their precipitous and ever-changing sides allow for substantial sediment movement away from shore. The Scripps Canyon is more precipitous and joins the La Jolla Canyon, which extends out to the San Diego Trough Fault Zone(SDTFZ). The narrow, steep-sided Scripps Canyon funnels the waves straight to shore, producing the powerful breaks of Black’s Beach. However, because Scripps Canyon takes a direct southward line to La Jolla Canyon, the two canyons meet at a nearly perpendicular angle, causing divergence in the paths of the waves.
Strong waves follow the course of La Jolla canyon to its head, terminating south of La Jolla Shores, just north of the sea caves. The strongest waves travel up Scripps Canyon toward Black’s. La Jolla Shores rests between these two areas, and avoids the powerful waves. Swimmers can enjoy the easy waves here, along with the bounty of ocean life (The Canyons are a marine sanctuary, the La Jolla Undersea Park, off limits to fishermen). Leopard sharks can be plentiful here, as well as rays and shovelnose guitarfish that inhabit the shifting waters of the intertidal zone.
Farther out to sea, the Canyons’ depth beckons migrating whales to the Undersea Park, and countless other varieties of fish, crustacean and mammal. Two artificial reefs have been sunk , attracting scuba divers and sharks to the deeper waters. La Jolla Cove draws snorkelers from all over and the underwater kelp forest is home to sea lions, seals and that ever-reclusive hermit, the black sea bass.
San Diego’s treasures of the sea center around the La Jolla Underwater Park and its two underwater canyons. Anyone can draw a once-n-a-lifetime experience from the ocean here: kayakers,surfers, scuba divers, snorkelers, waders and bodyboarders abound. The Scripps Aquarium exists here almost solely due to the environmental treasure trove on its doorstep. The California Pacific Coast gets no better than this.