Apprentices for the Upper Coastal Area must be taken by full branch pilots only with the approval of the South Carolina Commissioners of Pilotage Upper Coastal Area and shall serve two years in Georgetown before receiving an initial short branch license. An apprentice must be taken on board vessels of every description so that the apprentice may become completely competent to discharge required duties. After holding an initial short branch license for one year, an apprentice shall receive a second branch license, which the apprentice must hold in service for one year, at the end of which the apprentice may receive a full branch or license. The South Carolina Commissioners of Pilotage for the Upper Coastal Area shall establish in regulation the tonnage and draft restrictions for each short branch license.