Which Rule mentions the conditions for using sound signals under specific regulations?

Rule 34 of the COLREGs addresses the use of sound signals in various navigational situations. This rule specifically outlines the circumstances under which vessels are required to use sound signals, such as during periods of reduced visibility or in specific maneuvers when vessels are interacting with one another. It emphasizes the importance of sound signaling as a means of communicating intentions and ensuring safety at sea, particularly when visual contact may be impaired.

In contrast, other rules referenced do not specifically focus on the conditions and requirements for using sound signals. Rule 30 pertains to the signals to be made in restricted visibility, while Rule 28 deals with the maneuvering and warning signals. Rule 26 outlines what sound signals should be used in certain conditions but does not detail the broader circumstances for when they should be employed. Thus, Rule 34 is the appropriate reference for understanding when and how sound signals are to be used under specific regulations.