Maintaining a proper lookout using human eye sight and hearing applies to boats under what circumstances?

Maintaining a proper lookout using human eyesight and hearing is required for all vessels under the International Regulations for Preventing Collisions at Sea (COLREGs). This obligation applies at all times, especially in conditions of reduced visibility, at night, in congested waters, and when navigating near other vessels. A proper lookout is essential for detecting other vessels, navigation hazards, and any changes in the environment to prevent collisions and ensure safe navigation.