84. INLAND ONLY Which signal must a power-driven vessel give, in addition to one prolonged blast, when backing out of a berth with another vessel in sight 0.5nm away?

When backing out of a berth inland with another vessel in sight, a power-driven vessel must sound one prolonged blast and three short blasts to indicate astern propulsion, as required by Inland Navigation Rules 34(a) and 34(g).