When you have a 112-foot tall rock that drops vertically into the sea, who can resist diving around it to see what lies beneath? Big Rock, off the north side of the west end of Santa Cruz Island, is just that—one chip off the old block, a real big chip.

The prevailing weather comes right at the rock, so it is not too often you can dive here. The waves batter away at the monolith, cracking away large chunks that fall into the sea. These large chunks, and the fact that this site is not often dived, is what makes this location interesting. Huge splinters of rock from the main rock have fallen away, lodging into the bottom below, creating a garden of underwater mini-pinnacles. Each pinnacle is a little bit different, depending on depth.

Let’s start at the bottom. The rocks start from a sand bottom at 50 feet deep. If you wish, spend some time here looking for the ghost shrimp that are common at this location. Halibut hunting is good in the surrounding sand if you are inclined to spearfishing.

Jumbled boulders surround the bases of the mini-pinnacles. Lobsters are present but few and small. Big tube anemones are common. Rockfish move in and out of the crevices.

Up the face of the pinnacles is where the real fun begins. This is great scallop-hunting territory. They are not huge but good sized and abundant. Other filter feeder populate the vertical faces and include feather duster worms, red gorgonian, and orange and white sea cucumbers. These particular varieties of sea cucumbers are small, no larger than the size of your little finger, and use plume-like tentacles to filter particles of food from the water to feed an ever hungry mouth. In places, they carpet the rock.

A variety of color is provided by patches of corynactis anemones. They form in colonies according to color, which varies from pink, to red, to even lavender. This is probably due to their “cloning” method of reproduction. Each animal next to each other is a natural clone. Furthermore, when a colony of one color comes in contact with another, a territorial rivalry ensues with minor anemone skirmishes of chemicals and stinging taking place along the borders.

Mixed in among the more sedentary invertebrates are the movers and shakers. Tiny crabs are abundant and interesting to watch as they forage. Nudibranchs move around too, if you can call it that, and they cruise these rocks as well. My favorite found here recently was the Hudson’s dorid with its white color, yellow pokadots, and yellow edge “racing stripe.” Also, competing here in the nudibranch speed contest is the equally beautiful but much more abundant Spanish shawl.

The mini-pinnacles top out at 15 to 20 feet below the surface. Some rise 30 feet vertically from the sand bottom. You may have to, however, get pretty close to get a sense of scale. This location is not known for great visibility. About 20 feet is average. Cleansing currents generally do not reach this spot and the frequent surge can keep the water stirred up. Also, the water is greener here, which is probably why the filter feeders do so well.

If you are into macro photography or hunting rock scallops, Big Rock would be a good bet if the weather is right.

Special thanks to dive boat Spectre for assistance in creating this article.

Dive Spot At A Glance
Location: North side of the west end of Santa Cruz Island. GPS N34°03.142′, W119°34.442′ (GPS for reference only. Do not use as your sole source of navigation.)
Access: Boat only.
Skill Level: All if calm.
Depths: 15 to 55 feet.
Visibility: Fair to poor. 20 feet average.
Photography: Excellent macro with a wide variety of subjects. Watch the surge! Wide angle good but only if the viz is good.
Hunting: Very good for rock scallops. A few small lobsters in season. Halibut on the sand.
Hazards: Surge and seas.