California is such a huge market, that I am not sure what to suggest. I do know that our broker,
https://boatinsurance.net/ (Boat Insurance Agency) does not mind referrals from me. Worth it to give 'em a call.
We placed our insurance thru this broker (insuring with Travelers) several years ago, since we found that Geico, aka BoatUS, was mistreating us in several ways.
Worth mentioning also is that just before making this change we had a new survey done. While our boat was newer than yours, we also had a recent Betamarine engine installed, and could show that our boat was/is in excellent condition.
Also perhaps worth reiterating again

is that while we talk about our present boat model and year, what we are really insuring is the
money we have put into the boat. If lost due to fire or sinking, that money is what I want back so that we can buy (or restore) a replacement that is equivalent to the present vessel.
Oddly enough, the value we assign and insure for is also significant if our boat is ever damaged. The insurance company will, after all, total it even if the damage is easy to repair BUT will cost more than the boat's insured value.
I am watching the repair $ vs insured value drama play out this month for a recent local starting-line collision that will require 30 to 50K in repairs (at boat yard rates) for each boat, One had it's bow pushed in about a half a foot and the other has a good sized hole in the hull. No injuries luckily. Both are well built "higher end" boats from good builders, Rumor is (and only one of several rumors) that at least one of the boats may get "totaled" and the owner will make a decision whether to buy it back and repair it.
So, yeah, absolutely gotta have liability insurance, and the option is always there to self-insure for hull/rig damage. I'm cautious, so have always had agreed-value coverage, from our first Ranger 20 to our present Olson 34.
No claims either... I try never to think about 40 years of premiums paid out!
