Guarentee what?
Omissions, errors, are generally disclaimer but misrepresentation may be thin ice for a surveyor if it can be proved. No surveyor can guarantee his report will buy you insurance. For example, "misrepresentation" such as his report stating that the CORTEN steel hull bottom is sound and seaworthy and suitable for offshore cruising, when in fact the surveyor had no experience or prior knowledge dealing with metallic hulls and a day later it is discovered by an expert that the hull is badly galvanically corroded and is why it sank at the dock. Forget the guarantee part, you take him to court and the surveyor better hope his liability policy is paid up!