Arch Rock

Arch Rock is the forty-foot sea arch at the east end of East Anacapa Island, the most photographed landmark in Channel Islands National Park and a longtime symbol of the park. The dive sits right beneath it, the only practical shore-entry site in the park outside of Santa Cruz. The Island Packers ferry from Ventura Harbor lands at a concrete pier near the arch, and a long metal ladder descends from the dock to the water about ten to fifteen feet below depending on tide. Divers and snorkelers stage gear on the dock, climb down the ladder, and swim out into a kelp bed that drops from a cobble shoreline to a sand floor at sixty feet. An underwater swim-through arch lies thirty to fifty yards east of the landing, tall enough for a diver in the middle, with shallow reef and kelp on either side, and divers usually cover both the landing kelp and the swim-through in a single dive.

The waters around Anacapa are unusually rich because the cold California Current meets warmer Southern California water along the island chain, and the upwelling that results feeds dense kelp growth. The Channel Islands National Marine Sanctuary surrounds the park's five islands, and Anacapa Island was the site of the first Channel Islands reserve, established in 2003 and expanded under the network of state marine reserves and conservation areas that followed.

The bare rock of the arch and the reef around the headland make the Arch Rock dive a rocky reef biome. Giant kelp anchored on cobble and rock and growing up through the water column to the surface adds a kelp forest biome. Around the rock, standing almost in open water off the east tip of the island, the open water makes a pelagic biome.

Access is shore from the ferry dock, with no boat anchorage allowed inside the cove. The Island Packers schedule constrains the dive window to roughly four to six hours on the island, and the long climb up the ladder with gear is the practical limit on the day. The crossing is mild on settled days, and the cove sits in the lee of the island on most northwest weather.

Fishing and spearfishing are not legal here. The Anacapa Island State Marine Reserve covers Arch Rock, the landing, and the entire northern and eastern shoreline of the island. All take of marine life, including hook and line, spearfishing, and lobster, is prohibited inside the reserve.