The best answer to your question is YOU have to do the research yourself. I have never carried there but If I did decide to go, I would do some serious map searches for schools, identify the zones and insure I wont be close either strolling in the harbor or the parking area, insure im not on government property at any time. Then if I felt confident im not violating any law then I would go.
You ultimately are responsible for your research and findings, dont trust anyone elses word. They wont get you out of jail if you inadvertantly break the law. Perhaps some people who have carried in Oceanside may chime in and give you some helpful info or pointers, inform you about Oceanside LE and how they have been trained and there stance, but please do your own research.