The commissioners of pilotage for the ports of Georgetown and Little River shall, from time to time, organize a board of examination for the port to which they belong, to consist of three nautical men, at least one of whom shall be a full branch pilot of the port to which they belong. Each such board shall examine all applicants as to their competency to work or manage vessels and, generally, to discharge the duties of a pilot. No license or branch shall be granted to any person unless he receives a certificate of competency signed by a majority of such examining board.