Blog

COLREG Guide

The International Regulations for Preventing Collisions at Sea (COLREG 1972), explained part by part in plain language.

All parts in this series

  1. 1

    COLREG Basics Every Watchkeeper Should Know

    A practical refresher on the Collision Regulations: structure, key rules and habits that keep the bridge safe.

  2. 2

    COLREG Guide 2: Rules 1-3 Application, Responsibility and Definitions

    Who and where the Rules apply to, the good-seamanship duty, and the key definitions.

  3. 3

    COLREG Guide 3: Rules 4-7 Look-out, Safe Speed and Risk of Collision

    These rules apply regardless of visibility: keeping a proper look-out, choosing a safe speed, and assessing risk of collision.

  4. 4

    COLREG Guide 4: Rules 8-10 Action to Avoid Collision, Narrow Channels and Traffic Separation Schemes

    Taking early, obvious action, the rules for narrow channels and fairways, and conduct within traffic separation schemes (TSS).

  5. 5

    COLREG Guide 5: Rules 11-14 Sailing Vessels, Overtaking and Head-on Situations

    This section applies to vessels in sight of one another: two sailing vessels meeting, the overtaking rule, and why both vessels alter to starboard in a head-on encounter.

  6. 6

    COLREG Guide 6: Rules 15-18 Crossing Situations, Give-way/Stand-on Duties and the Vessel Hierarchy

    Who gives way in a crossing situation, what the give-way and stand-on vessels must each do, and which vessel type outranks which.

  7. 7

    COLREG Guide 7: Rule 19 Conduct of Vessels in Restricted Visibility

    What changes when fog, rain or snow hides other vessels from view.

  8. 8

    COLREG Guide 8: Rules 20-23 Introduction to Lights and Shapes, Definitions, Visibility Ranges and Power-Driven Vessel Lights

    When lights and shapes must be shown, the definitions of masthead/side/sternlight, minimum visibility ranges by vessel length, and the standard light configuration for power-driven vessels.

  9. 9

    COLREG Guide 9: Rules 24-27 Towing and Pushing, Sailing Vessels, Fishing Vessels and Vessels Restricted in Manoeuvrability

    The lights for towing and pushing vessels, sailing vessels and vessels under oars, fishing vessels, and vessels not under command or restricted in their ability to manoeuvre.

  10. 10

    COLREG Guide 10: Rules 28-31 Vessels Constrained by Draught, Pilot Vessels, Anchored/Aground Vessels and Seaplanes

    The lights and shapes for draught-constrained vessels, pilot boats, anchored or aground vessels, and seaplanes.

  11. 11

    COLREG Guide 11: Rules 32-34 Sound Signal Definitions, Equipment and Manoeuvring/Warning Signals

    What counts as a short or prolonged blast, which sound equipment each vessel must carry, and what each whistle and light signal means.

  12. 12

    COLREG Guide 12: Rules 35-38 Sound Signals in Restricted Visibility, Attracting Attention, Distress Signals and Exemptions

    The fog-signal patterns for every vessel type, how to attract another vessel's attention, distress signals, and the exemptions COLREG grants to older vessels.

  13. 13

    COLREG Guide 13: Common Mistakes and Lessons

    The recurring human errors behind collisions and how to avoid them.

  14. 14

    COLREG Guide 14: Exam Preparation and Memory Techniques

    Understand the Rules instead of memorising them: practical study methods for exams and for the bridge.