What is the minimum action a vessel must take if she hears another vessel's sound signal?

When a vessel hears another vessel's sound signal, the appropriate action to take is to take all way off. This means reducing speed and ceasing forward motion to prevent collisions or dangerous situations. Sound signals are critical in maritime navigation, particularly in restricted visibility conditions, as they communicate a vessel's intentions and maneuvers to others nearby.

Taking all way off ensures that a vessel is safe and can make decisions based on the situation around it. It allows the crew to assess the surroundings and determine the best course of action, whether that means altering course or stopping entirely.

In scenarios where a vessel does not respond appropriately to sound signals, such as turning around or increasing speed, it could lead to misunderstandings of intentions and increase the risk of accidents. Ignoring the signal altogether does not align with safe navigation practices and could result in serious maritime incidents.