I've got to think that if the surveyor knew his stuff, he'd KNOW he can't discuss values other than with his client. Surveyors that provide a VALUE, are by definition appraisers (I'm a real estate appraiser, and a
classic car appraiser). They should be guided by USPAP (Uniform Standards of Professional Appraisal Practice) - and this includes STRONG confidentiality requirements.
When we bought our
boat, I did make it clear to the surveyor that the
survey was mine and only mine. The
broker got pissed when I wouldn't give him a copy or allow the surveyor to provide a copy or even talk about it. I told him "I paid for the
survey, so the survey is mine and I have no intention of sharing it with you".