Three short blasts (International and Inland) convey which meaning?

• A. I am altering my course to port
• B. I am leaving berth
• C. I am stopping propulsion
• D. I am operating astern propulsion

Answer: (D)

Three short blasts are the signal that you are using stern propulsion. This is a standard maneuver signal under both International and Inland rules, and it tells other vessels that you’re backing up or moving astern. The purpose is to warn nearby traffic that your vessel will be reversing, so they can adjust course or speed to stay clear.

You’d use this cue when backing away from a berth or maneuvering in tight quarters, where reversing could affect nearby vessels. The other options describe different actions or signals and do not correspond to the pattern of three short blasts, which is specifically tied to backing with stern propulsion.