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 0.5 nm away?

Correct Answer: Option C — 3 short blasts

33 CFR 83.34(a) mandates that a power-driven vessel operating in or near an obscured area or backing out of a berth must sound one prolonged blast. Additionally, 33 CFR 83.34(a)(ii) requires three short blasts to indicate that the vessel's engines are operating astern propulsion.