BOTH INTERNATIONAL & INLAND A vessel nearing a bend or an area of a channel or fairway where other vessels may be hidden by an obstruction shall __________.

Correct Answer: Option C — sound a prolonged blast

COLREGS Rule 34(e) requires any vessel nearing a bend or fairway area where other vessels may be obscured by intervening obstructions to sound one prolonged blast, which must be answered with a prolonged blast by any approaching hidden vessel.