What does the term "restricted visibility" refer to?

The term "restricted visibility" specifically refers to situations where visibility is significantly reduced due to environmental factors such as fog, rain, mist, or snow. This definition is crucial in maritime navigation as it requires specific actions from vessels to avoid collisions. When visibility is impaired, it is essential for vessels to adhere to the prescribed regulations that address navigation, sound signaling, and lookout responsibilities in such conditions to enhance safety on the water.

The other options do not accurately encapsulate the meaning of "restricted visibility." Conditions where vessels are at anchor do not necessarily imply any reduction in visibility. While poor weather may contribute to restricted visibility, it does not define it; thus, the broad statement of "all conditions of poor weather" lacks the specificity that "restricted visibility" entails. Lastly, vessels maneuvering incorrectly relates to operational errors rather than a description of visibility conditions.