It is ironic that the previous comments have forgotten one of the very best sources. Search the web, especially sites devoted to that make and/or model.
I was very interested in a boat not too far from here and by using the Internet, learned that there was post compression, deck leaks, that the new engine didn't match the propeller, and that the sails were NDG. The seller knew all this but did not disclose it to the broker or to me -- at least that is what the broker said. So, apparently the plan was for me to negotiate an offer as if the boat was as advertised, spend several hundred dollars to discover the truth -- best case -- and then try to negotiate a more reasonable price.
I have two rules of thumb when buying used cars -- that I do a lot-- and I think that they apply. The first is that the seller is the most important variable. If you can believe in the seller (previous owner), then 90% of your problems disappear. Second, no one sells a vehicle that they are perfectly satisfied with. That would be ridiculous. If you can identify the straw that broke the camel's back, then you can make a very reasonable purchase. If you can't, then it is still important to rely on your assessment of the seller. Sometimes, it was the last repair they had to pay for -- that is terrific.
In my case, I was able to force the seller to divulge more of what they knew, including sharing the previous survey. I did not buy the boat, but it was purely a difference of opinion about reasonable price.
There are many protections in CA for home buyers, especially regarding disclosure of known problems. There ought to be something similar for boats and cars -- in my opinion. At a minimum, do Internet due diligence and see what you can find.