Most insurance companies will require an insurance survey when issuing cover on an older yacht, and will require the survey to be undertaken every further 5 years.
The purpose of the insurance survey is to identify any defects in the vessel that would represent an unacceptable risk to underwriters. Such defects could be found in the structure and structural attachments, ballast, steering system, gas system, electrical systems, sails and rig, deck fittings, ground tackle, windows and hatches, through hull fittings and their hose attachments, propulsion equipment and engines, safety equipment, tank and fuel installations, bilge systems, and navigation equipment.
The scope of work is not far short of the pre-purchase survey, but the range of advice tends to be significantly less, so this is usually a less expensive survey.
In the body of the report there will usually be additional recommendations on other issues that will have been noted while conducting the insurance survey. However at the end of the report and there will be a list of those recommendations required to be completed in order to meet the requirement of underwriters.
Most insurance companies will accept notification from the owner when the required recommendations have been carried out, so a follow up inspection is rarely required.