I second Russian Gulch.
However, to get out to the better structure you might want to use a kayak. It can be done from shore but it is quite a long surface swim to get past all the blah. If you do shore dive it, stick to the right side along the wall and it progressively gets better and better as you go out.
Albion can be great too but it’s also best done from a kayak.
There is one really great shore dive that I should mention off of the Mendocino Headland. Drive through the town of Mendocino and go out to the headland. There is an area to park along the road with a long pull out. You will see a land bridge formed by rocks and to the right of the land bridge is another land mass. These two promonories form a channel about 20’ wide, and it’s about 35’ deep right where the two points come together. They also form a beautifull cove inside that is very calm but it’s a bit of a hike to get down to. There are two trails down. The one on the right side is long but not as steep, and the left side (land bridge side) is steep but shorter. If you decide to climb down to the end of the landbridge side you can giant stride right off the edge of the rock and you’ll be in 35’ of water! It depends on how sturdy you feel you are doing some hiking/climbing in scuba gear.
In between these two land masses is what they call “The Pipe”. It’s an old decommissioned sewer pipe that runs fown in between the land bridge and the other land mass. Follow the pipe down through terrain that cascades down with all sorts of little mini walls and buss size boulders down to about 65’ into the gravel where the pipe ends. There are some big Cabezon hiding under the pipe in places where it’s elevated and some good size lingcod too. There used to be abalone everywhere through there and of course all the test of the stuff you’d normally see. If you look hard enough you might see a wolf eel or an octopus.
Also, Van Damme can be a great dive if you have a kayak and can manage to get out past the furthest rock, which is the “Keyhole”.
*On a good day*, you can anchor right on the outside edge of the Keyhole rock and five the outside, which is a wall dive that cascades down to about 120’.
Once at the base you will see several symetrical sand channels that form what look like city streets with towering buildings on either side with intersections, very bazaar and interesting. It’s deep though so watch your time because it’s easy to get caught up in wanting to see what’s around the next corner. And it’s easy to get lost, which also might mean you’ll be doing a free ascent out in open ocean in a boating lane, so pay attention and find your way back to the wall you came down to find your way back to your kayak. On the way up the wall I have seen a lot of cool stuff. It’s a great wall to do some deco on.
Hope all that helps.
Happy diving!