Go down to Big Sur south of Monterey and you can see whales this time of year cruising by. I was fishing and saw many sea otters and dolphin pods go by.
Check the Monterey bay Aquarium. Really a sight to see when you're there.
I love the ocean and I explore it a lot. There's a place on Hwy 1 about 23 miles south of Half Moon Bay called Bean Hollow State Beach. That place is absolutely magnificent. You can walk on the reefs and rocky areas and venture out far during a low tide. In the tidepools you will see small baby fish, variety of crabs and snails and sea anemones.
Here's a link to the californiacoastline.org site that shows it. Click on the picture for higher res pics.
Bean Hollow
If you want to explore north of SF, go to Point Reyes National Seashore. Nice views for sure from the lighthouse.
Lots of places around here. Depends on what you want to do.