For a storm warning during the night, what is the signal used?

The correct signal for a storm warning during the night is two red lights. This signaling method is part of the established maritime communication protocols to alert vessels and crews of imminent severe weather conditions, specifically storms.

Using two red lights is universally recognized in maritime operations as a clear signal of danger, particularly related to weather. This method ensures that the signal stands out distinctly at night, allowing for immediate visibility and recognition by mariners, who may need to take precautionary measures to secure their vessels and ensure crew safety.

Other options, while they may represent different signals, do not specifically denote a storm warning at night. For example, a single red light may not convey the same level of urgency or specificity. Likewise, other signals like white over red or a red pennant serve different purposes in maritime signaling, such as indicating different types of warnings or statuses rather than a direct storm alert.