What is Standard Note 4?

• A. Loss of Power
• B. Loss of System
• C. Loss of Water
• D. Loss of Air

Answer: (D)

Standard Notes in CSOSS are predefined response sequences for specific casualty conditions, with each note number tied to a particular type of loss. The fourth note is the one that governs a loss of air, meaning the ship’s ventilation or air supply has failed or is compromised. That’s why Loss of Air is the best answer: it matches the casualty type that Standard Note 4 is designed to address, guiding the crew through the immediate steps to restore breathable air and maintain safety. Other options describe different casualty conditions—loss of power, loss of water, and loss of system—which are handled by their own standard notes and procedures, not the fourth.