San Mateo Scuba Diving locations & information provided by MITCHELL SCUBA.

Left pic is parking lot at Linda Mar Beach - Right pic is Linda Mar Beach & Pedro Point to the South.
LINDA MAR BEACH DIVE SITE INFORMATION
BEACH AND KAYAK DIVES
(SKILL LEVEL: ADVANCED TO EXPERT)
Linda Mar Beach is a sandy beach with a gradually sloping bottom. The depths in close are up to 20 feet or so, but if you go out about ¼ mile, the bottom drops down to about 30 feet, and the sand gradually gives way to a fairly well defined reef system which parallels the beach. It is usually safest to enter the water at the South end of the beach, adjacent to the cliff. If you follow the cliff out you will notice a gated entrance at the top of the cliff about half way out to the point (Pedro Point). This gated entrance is a good reference point to find the reef system which runs North to the other end of Linda Mar Beach. This beach is a very popular surfing spot, and I advise caution when entering and exiting.

This would definitely not be a good entry or exit point for a Scuba diver.
There is also an old barge laying at the bottom of the cliff in about 10 - 15 feet of water. The wreckage runs for about a 100 feet or so and is immediately adjacent to the cliff. It was blown up many years ago because it was a hazard to navigation. You can still see the old steel plates piled up on the bottom. The many cubbyholes, nooks, and crannies are a very good place for ling cod and cabezon to hide out. This beach is also a good spot for halibut, but the poor visibility makes them difficult to spot.

At the parking lot there are also toilets and two outside showers. The showers are heavily used by surfers, and are unsuitable for anything but a very quick rinse of your gear. There are also posted restrictions on "events" without a permit.
To get to Linda Mar Beach take Coast Highway 1 South from S.F. until you get to the public parking lot across from Linda Mar Blvd. There is a Taco Bell at the South end of the Beach.
The decision to dive (or not) is your responsibility. Keep diving activities within your training and comfort level. If you feel more training or experience is needed before attempting a dive, don't dive. Know personal limits, skill levels, and abilities of yourself and your dive buddy. Dive Safely and Dive Often!
If you have any questions, concerns, or comments, contact me