The sternlight shall be positioned such that it will show from dead astern to how many degrees on each side of the stern of the vessel?

The sternlight on a vessel is designed to illuminate the area behind the vessel to ensure visibility to other vessels approaching from the rear. According to the navigation rules, the sternlight should be positioned to show from dead astern—directly behind the vessel—to a specified number of degrees on each side.

The correct answer indicates that the sternlight shows from dead astern to 67.5 degrees on each side of the stern. This positioning is essential for improving navigational safety during nighttime operations or in low visibility conditions, allowing other vessels to see the sternlight well within a proper range that enhances situational awareness. This 67.5-degree angle ensures a significant area of coverage while preventing light overlap that might confuse other vessels about the navigation lights being shown.

Understanding this specification is vital for compliance with navigational rules and for safe maritime operation. It aligns with the established standards set forth in the International Regulations for Preventing Collisions at Sea (COLREGs), ensuring that vessel operators maintain proper lighting to indicate their position and heading accurately.