One of my graphic design clients practices maritime law. If I need to, I'll give him a holler.
it would definitely be worth a quiet beer to have a casual conversation with your client/maritime lawyer about what to expect, and to see if he is interested/available/appropriately skilled/has recommendations in working with you on this should it be necessary.
sorry for the mangled syntax there.
try not to stress too much. hopefully its just wood and fiberglass and minor inconvenience. it may make a good story some day...