Arch Rock on the east end of the East Island of Anacapa is the symbol of the Channel Islands National Park. Its sweeping grandeur is one of the most beautiful ocean scenes in the world. Gulls and pelicans are in constant motion around the rock edifice as the blue sea swirls below kelp lapping at the surface.
As beautiful as this is there is a vista nearby that rivals the beauty of Arch Rock, only this location is underwater and, consequently, seen by far fewer people. You are one of those lucky divers who can visit this beautiful site. Just around the corner from Arch Rock, on the south side of the east island, is an underwater arch that is easy and fun to dive when the conditions are right. This backside underwater arch lies in only 35 feet of water. The reef that makes up the arch is vibrant and covered with life and thick kelp. At 15 feet tall and about 35 feet wide, the arch is easy to pass from one side to the next and back again. Soft ivory sand form its base and a multitude of fish enjoy the shade of its roof.
Much of the marine life here is typical of what you might expect to find at any Anacapa Island reef (which can have some of the most beautiful kelp forests in all of the Channel Islands). Sheephead and kelp bass are on the large side (but not huge) and lobster can be found in the surrounding rocks. This was once a very good location for rock scallop hunting, but heavy pressure has now made it sparse.
Lush kelp holds schools of blacksmith fish, señoritias and jack mackerel. Across the reef dance garibaldi, painted greenlings, and tiny blue-banded gobies.
This is an excellent area for photography—both macro, for abundant small fish and invertebrates, and wide angles taking in kelp vistas and, of course, the arch. The best wide-angle shot is from the shoreward side looking out. Light will filter through the arch making for good backdrop for divers and/or fish. Macro photographers will have no problem finding subjects like nudibranches of many shapes, sizes and colors, shrimp, and mollusks, including the shiny chestnut cowry.
This site does, however, have its problems. It can be surgy, or even undiveable, if a strong south swell is running. Also, currents are frequent, although less of a problem close to shore at the arch.
Anacapa is actually full of arches and small caves. This is owed to its geological origins. The rock that makes up the island and its reef is mostly igneous, (volcanic) in nature. In formation, gas pockets and weak spots formed. As the ocean eroded the rock face, caves and arches were carved out at those weak points.
Because this is a relatively shallow dive, take the time to also explore the surrounding reef. The tall ridge that makes up the arch has many interesting crevices and a beautiful kelp forest. The ridge comes up as shallow as 12 feet and runs roughly parallel to shore.
Dive Spot At A Glance
Location: South side of East Anacapa Island, 50 yards directly off a small islet.
Access: Boat only.
Skill Level: All
Depths: 15 to 35 feet
Visibility: Fair to good, averaging 30 feet.
Hunting: Fair spearfishing, a few scallops and lobster.
Photography: Excellent wide angle in kelp and with the framing of the underwater arch. Abundant macro subject including small fish and invertebrates.
Hazards: Surge and currents. Kelp can also be especially thick at times.