In the event of an accident, your insurance company is likely to instruct an independent marine surveyor to obtain details and to assess the extent of any damage. In this situation, the surveyor's client is the insurer, to whom he must report. If you are not comprehensively insured, or you think that a third party may be responsible for the incident or damage, or have other concerns, you might want to consider engaging an independent surveyor in order to look after your own interests. Take some digital photographs as soon as you can for your own records.
If, once the repair work is under way, you have any concerns about the work being done, engage an independent professional surveyor as soon as possible. A lot will depend upon your agreement with the yard, viz contracts, estimates, quotations and variations, but an independent surveyor may well be able to help significantly, particularly if there has been a breakdown in relations and emotion has crossed swords with business. Choose a surveyor that has appropriate expertise for your job.