Pat Lovejoy has done a nice job on
http://pt-lobos.parks.state.ca.us/scuba/
You must enter down the boat ramp.
Climb up the trail at the back of the parking lot and get
a good overview of Whaler's Cove. Note the channel
out through the kelp. NOTE IT WELL. It is your friend.
Don't bother diving right in front of the ramp. It's boring
sand. Hang a left and swim out the channel. The depth
is about 20' where the channel begins, about 75' at the
mouth of the cove, with a gradual slope between. Drop
at whatever depth you are comfortable in, and work
your way back towards the launch ramp. Leave PLENTY
of air to swim under the kelp. I'd plan on being on top
with 700 PSI. Surface, find the channel, swim UW to
the channel, then surface swim back in.
The kelp in Whaler's is about the thickest kelp anywhere.
I've personally helped three people out of the middle of
it who were on the surface, OOA, and had gotten all
wrapped up in it struggling.