I first dove at Mackerricher about 2 years ago. It has since become one of my favorite California shore dives. It has a labyrinth of canyons abundant with sea life. The swim out is just as interesting as the dive. On one dive we encountered a salp (there are many different kinds and I don't know the full name of this one), a jelly-like creature that was shaped like a transparent milk bottle with horns. The south side can be treacherous, but is diveable during calm seas. A tank cart or dolly is recommended to tote your gear to the entry point. If you choose to exit your dive on the beach, beware of the seaweed, as you'll probably be dragging a bunch up with you. I haven't seen a lot of scuba divers here, but there are more abalone divers during ab season. Parking is limited, and can fill up quick on weekends and holidays. My deepest dive here was about 55 feet. This is an excellent site for beginners to advanced, and snorkelers as well.