Wouldn't recommend diving Santa Cruz, there's nothing to see.
The only place "frequented" by diver's in SC is the west side of the wharf at Cowell's beach (next to the boardwalk). But conditions are always crummy.
The Lifeguard's in the tower also ask for divers to bring a dive flag/float/buoy when diving.
UCSC's Rescue and sci dive class performs their rescues and searches in that area. Visibility is always crap, it's shallow and usually surgey. Entries and Exits are really tricky and tough. The ocean waves are a challenge to break through on entry especially if you're not used to it (the area is a surf spot so no surprise really).
On entry and exit you have a really good chance for getting picked up and tumbled, especially if the waves get above head height.
Outside the wharf there's nothing but sand, sand dollars, hermit crabs, and flat fish.
Under the wharf you'll experience night dive conditions with often near zero viz because of the detritus or sand particles. You'll get to see numerous identical pylons with anemonies, starfish, juvenile fish etc. The bottom usually has a lot of detritus and some trash items. The only good news is the surge stops right after you get past the first pylons.
I would not recommend diving the wharf or the area around it unless you're training and have some experience with rough conditions and navigation. If you're looking purely for a fun relaxing dive then you should go to Monterey. Sorry buddy....
