Mendocino Bay is a shore accessible salt water dive site, located in Mendocino, CA. This dive site has an average rating of 3.00 out of 5 from 1 scuba divers.
This dive site may be found on the North coast of Mendocino Bay. This wonderful diving beach is also known as The Blow Hole, due to a large hole in a cave to the right of the beach. The cave itself is known for a spectacular collection of nudibranches. Other critters can, of course, be found in the kelp field just off shore.
At the South end of Mendocino, take Main Street toward the ocean.
I have dove this site from 1993-2000 many times and 3 more times since I moved away. The coolest part was the WALL OF ABALONE! Either start from the beach and thru the tunnel or walk out past tunnel end & down the steep rock edge. Dive to westside of tunnel entrance and head south around the rock face and you will find a 20ft tall wall some 30-45ft long covered with large abalone about 45ft deep. Lots of bull kelp and a bottom covered in broken shells, and it is best done on a calm day because of the heavy surge.
This place has probably seen more people then any other site in Mendocino county. Mainly because this beach is where all the locals hang out and watch their children. As for the blow hole, there are lots of broken and whole ab shells (found some really nice baby ab shells) and what appears to be old car/wagon parts. I asked a local and was told that back in the day people would use the hole as a dump. So overall if you’re into finding shells and seeing a local sea fill, this is a great place. Otherwise better off at Russian Gulch or Van Dam.
http://www.shorediving.com/Earth/USA_West/CalN/Mendocino_Bay/index.htm