When requested in writing by any person interested, port wardens shall survey any vessel which may have suffered wreck or damage, or which may be deemed unseaworthy. Such port wardens shall call to their assistance one merchant and one shipwright, both of whom shall be competent and disinterested persons and shall be sworn faithfully to perform their duties in the examination and survey. Said surveyors and port wardens shall examine the hull, spars, sails, rigging and all the appurtenances of said vessel, and make and record in the books of the port wardens' office a full and particular report of all the surveys by them held on said vessel, specifying what damage she has sustained and what repairs in their opinion are necessary to render her again seaworthy. The aforesaid report shall be presumptive evidence of the necessity of such repairs and of the sufficiency of the same when made.