Question 393Navigation General

The correct answer is B) Two long blasts. The US Coast Guard Navigation Rules and Regulations Handbook states that the signal for "Permission to enter the riverward chamber of twin locks" is two long blasts of the ship's whistle. This is the standardized sound signal that a vessel must make to indicate they have received permission from the lockmaster to enter the riverward chamber of the twin locks. The other answer choices are incorrect because a single short blast (A), two short blasts (C), or a single long blast (D) do not correspond to the established sound signal for this specific circumstance as defined in the Coast Guard regulations.