The area has a special closure around the offshore rock there as part of the Marine Life Protection Act. Details at http://www.dfg.ca.gov/mlpa/ - click on North Central region. The rock there is called Egg Rock (and actually covers all the offshore rocks there). You are supposed to stay 300 feet outside of them, and not got between them and shore. Year round (though truthfully, the main worry is during sea bird breeding season, which at its broadest would be March to August. To get to the closure info, there is a special PDF at http://www.dfg.ca.gov/mlpa/pdfs/ipa_closures.pdf that lists them (most of the changes are related to fishing, but in this region there are 5 or 6 areas that are closed to all boats).
That area also falls under the Monterey Bay National Marine Sanctuary (Pacifica, where you launched, is not, but you entered it once you rounded the point going south). They may have their own rules, but I don';t think any closures to kayaks or other boats.
That area does get a lot of watching from bird people, so your being there was likely noted.
Keep in mind that that area is open ocean and sh!t can happen. Here was an incident off of Devil's Slide that happened to the Neptune's Ranger guys about a year ago: http://youtu.be/h2M5aztpOQk. Full disclosure - that first clip in the video was taken by me.