Westdahl Rock

Westdahl Rock is a spread of jagged pinnacles 1.3 miles southwest of the Point San Luis lighthouse, outside the shelter of the point and reached by boat from Port San Luis Harbor. NOAA charts 18 feet of water over the shallowest top, rising abruptly from a floor at 60 feet, and the tops across the wider site sit around 20 feet with the outer edges falling to about 70. A lighted bell buoy marks the rock for vessels working into San Luis Obispo Bay from the north, which makes the site easy to find.

Steep rock towers standing 40 feet and more off the surrounding floor, several of them close together, put a pinnacles biome across the whole site. The open water moving over and between those towers, carrying larger fish and seasonal pelagic species, is a pelagic biome.

Underwater photography is the strongest reason to dive here, since invertebrate life covers the rock heavily and the fish counts are moderate. Scuba and spearfishing both happen at the site. The position southwest of the point is the constraint: Westdahl Rock sits outside the wind and swell shadow that makes the rest of San Luis Obispo Bay dependable, so it is a settled-weather dive.

There is no MPA at this site. Hook-and-line fishing and spearfishing are legal here under standard California regulations.