COLREGs Quick Reference Guide for Day Skipper

The International Regulations for Preventing Collisions at Sea (COLREGs) are the 'rules of the road' for vessels on the water. Every skipper must know them. The Day Skipper syllabus requires 'full' knowledge of the steering and sailing rules — meaning you need to know them thoroughly, not just have an outline understanding.

The COLREGs apply to all vessels on the high seas and connected waters navigable by seagoing vessels. There are 41 rules in total, plus annexes covering lights, sound signals, and distress signals.

Rule 18 establishes which types of vessel must keep clear of others. From most restricted to least restricted: a vessel not under command, a vessel restricted in her ability to manoeuvre, a vessel constrained by her draught, a vessel engaged in fishing, a sailing vessel, and a power-driven vessel.

A useful mnemonic is 'New Reels Catch Fish So Purchase': Not under command, Restricted in ability to manoeuvre, Constrained by draught, Fishing, Sailing, Power-driven. Each vessel in the list must keep clear of those above it.

Rule 12 covers sailing vessels approaching one another. When two sailing vessels are on opposite tacks, the vessel on port tack keeps clear. When both are on the same tack, the windward vessel keeps clear. If a vessel on port tack cannot determine whether the other is on port or starboard tack, she must keep clear.

Rule 13 (overtaking), Rule 14 (head-on situations between power vessels), Rule 15 (crossing situations between power vessels), and Rules 16–17 (actions of give-way and stand-on vessels) are all heavily examined. Remember that the stand-on vessel must maintain course and speed initially, but must take avoiding action if the give-way vessel fails to act.

Power-driven vessels under 50m show: masthead light (white, 225°), sidelights (green starboard, red port, 112.5° each), and a stern light (white, 135°). Sailing vessels show sidelights and stern light only — no masthead light.

At anchor, vessels show an all-round white light (or two if over 50m). Vessels not under command show two all-round red lights in a vertical line. Vessels restricted in ability to manoeuvre show red-white-red vertically. Learn these patterns — they are frequently examined.

In restricted visibility, power-driven vessels making way sound one prolonged blast every two minutes. Power-driven vessels stopped sound two prolonged blasts. Sailing vessels, fishing vessels, and vessels restricted in manoeuvrability sound one prolonged and two short blasts.

In sight of one another, manoeuvring signals are: one short blast = I am altering course to starboard; two short blasts = I am altering course to port; three short blasts = my engines are going astern. Five or more short blasts = I am unsure of your intentions.