Don't expect it to be easy, I'm in CA too. With OT exhaust all the insurers I talked to turned me down. I've not found sufficient insurance in 13 years.
For all those who claim they have it, 99% of them misrepresented the boat. This is a false sense of security because if there's ever an incident where the insurance company gets involved, once it's discovered that the boat description was fraudulant the insurer will abruptly cancel your coverage and leave you hanging. So in effect the premiums are paid for nothing.
Rk