That every ship or vessel bound to the Delaware breakwater for orders shall be obliged to receive a pilot, provided she is spoken or a pilot offers his services, outside of a straight line drawn from Cape Henlopen Light to Cape May Light, and every ship or vessel bound to the breakwater for orders shall pay pilotage fees as follows: A sum equal to half the pilotage to the Port of Philadelphia, and she shall be obliged to take a pilot and pay the same pilotage fees when outward bound, from the breakwater, and if such ship or vessel, without discharging her pilot, proceed to the Port of Philadelphia or any other port or place on the bay or river Delaware, only one full pilotage fee as fixed by section 3.1 of this act, for the entire service, in addition to the fee for detention: Provided, however, That if the pilot bringing such ship or vessel to the breakwater be there discharged, and the ship or vessel afterward proceed to Philadelphia or any other port or place on the bay or river Delaware, she shall make the usual signal for a pilot and continue to make such signal till reaching Brandywine Light, and if spoken by, or offered the services of, a duly licensed Pennsylvania pilot before reaching Brandywine Light, shall be obliged to employ such pilot and pay him for services rendered on and after the effective date of this act, a charge computed as follows: