Point Dume in Malibu. On the left side of the beach is a nice kelp forest, directly from the beach nice rocks and some kelp and to the right ( little swim out there is a seal rock with some kelp as well. However you have to watch for current if you go to the seal rock and also float with dive flag is a must since there are some boats around. ( as everywhere else I suppose.)

At this location you can park on top of the hill and then take the stairs down right to the beach, however it's only 2or 3 hour parking. So you may need to park on the street couple of blocks away. Or go to a Zuma beach to the pay parking there and then walk to the end of the beach on left and get in the water there and swim aroun the point Dume cliff ( around the seal rock.
Then Leo Corillo at the end of Malibu has a very nice kelp forest there.
I will be training for dept this week , but I think one day this weekend I want to go out there and just have fun. So let me know if you will be interested.
Vaclav