Key Points

Rule 4 - Application

• Rules 4-10 apply in any condition of visibility - clear weather, fog, rain, or any other conditions.
• These rules form the foundation for safe navigation and must always be followed.

Rule 5 - Look-out

• "Every vessel shall" maintain a proper look-out - this means there are no exceptions.
• A look-out is required at all times - not just during restricted visibility, at night, or in heavy traffic, but always.
• A vessel at anchor is still required to maintain a proper look-out.
• The look-out must use sight and hearing as well as "all available means appropriate" to the circumstances (including radar, AIS, VHF, etc.).
• The purpose is to make a full appraisal of the situation and assess the risk of collision.