COLREGS (International Regulations for Preventing Collisions at Sea, 1972) is the internationally agreed traffic code every vessel must follow at sea, governing vessel movement, navigation lights, fog signals, and right-of-way rules.
Core Structure
COLREGS is organized into 38 Rules across 5 Parts: Part A (application and definitions), Part B (steering and sailing rules — the operational core covering give-way/stand-on responsibilities), Part C (lights and shapes), Part D (sound and light signals), and Part E (exemptions).
Why It’s the Foundation of Safe Navigation
COLREGS exists because vessels approaching each other need predictable, universally understood rules for who gives way and who holds course — without this shared traffic code, every close-quarters situation would depend on ad-hoc judgment calls between vessels that may not share a language or navigation culture.
Exam Relevance
COLREGS Rule structure, give-way/stand-on vessel responsibilities, and navigation light/signal interpretation are core, heavily tested topics across every level of deck officer competency exam.