🔍 Key Concepts

• Submarines on the surface special identification lights • Distinction between standard navigation lights and special-purpose identification lights • Where in the Navigation Rules / COLREGS submarine identification is addressed

💭 Think About

• Which of these light colors and characteristics is NOT commonly used for normal surface navigation lights on merchant/commercial vessels? • Think about why a submarine on the surface might need a unique, easily recognizable light that will not be confused with masthead, sidelights, or towing lights. • Consider which option sounds like a dedicated identification signal rather than part of the regular running light system.

✅ Before You Answer

• Eliminate any lights that resemble standard running lights (sidelights, masthead, stern). • Recall whether blue lights are normally reserved for law enforcement or special services rather than submarines. • Verify in the Navigation Rules which color and flash pattern is listed as the submarine identification light.