It is north of Cresant bay a couple of miles at the most. Im pretty sure you have to pay to park there, its a marine reserve. They do have outside showers to rinse yourself and gear off at the top of the stairs, but its a very long walk. The term divesherpa comes to mind. its almost an expedition. No to brag, but in my younger days i dove it with 2 genisis 100s and a deco bottle. however i would never do it again.
Theres no beach access, but before you get to Crystal Cove theres a surfing spot called Abalone Point. I did dive it a few times but the swim is half a mile. You have to enter at cystal cove and swim to the next point south ( abalone point). You can walk down the beach to the point in your gear but its a hell of a walk in the sand. Only dive there on a flat calm day or else your wasting your time. its not a surfing spot for the small waves hint hint.
this may help you:
all those old homes on the beach that had been in the news about there lease expireing. The only true beach homes from the 50's and 60's that were left in laguna. All those homes were sitting on the beach at abalone point. They lost the battle to stay and were all evicted. It was big news here, i hope you remember.
Andy