Module 5 - COLREGs
COLREGs Explained for Day Skipper: Rules of the Road
Quick answer
COLREGs are the International Regulations for Preventing Collisions at Sea. Day Skipper students use them to decide lookout, risk of collision, give-way action, lights, shapes, and sound signals.
- The rules apply before, during, and after a close-quarters situation.
- Start with lookout and risk of collision before deciding who gives way.
The International Regulations for Preventing Collisions at Sea are known as COLREGs or IRPCS. They are the rules of the road at sea and explain how vessels should keep a lookout, assess collision risk, give way, stand on, display lights and shapes, and make sound signals.
COLREGs apply to all vessels on the high seas and connected navigable waters. As a Day Skipper, you need full knowledge of the steering and sailing rules, especially Rules 5, 7, 8, 9, 10, and 12-19.
The regulations are divided into parts: Part A (General), Part B (Steering and Sailing Rules), Part C (Lights and Shapes), Part D (Sound and Light Signals), and Part E (Exemptions). In exam questions, always identify the situation first: overtaking, head-on, crossing, sailing vessel, narrow channel, restricted visibility, or special vessel type.
This page is an independent study guide. For navigation and safety decisions, check the current COLREGs and official notices rather than relying on any revision aid alone.
Look-out
Risk
Action
Responsibilities
Lights & shapes
Key points
- COLREGs apply to ALL vessels on navigable waters
- Part B (Steering and Sailing Rules) requires full knowledge
- Rules exist to prevent collisions — both vessels share responsibility
Look-out
Day Skipper exam focus: Sight, hearing, radar, AIS, and all available means
Risk of collision
Day Skipper exam focus: Constant bearing, decreasing range means danger
Action to avoid collision
Day Skipper exam focus: Act early, positively, and obviously
Sailing, overtaking, head-on, crossing
Day Skipper exam focus: Who gives way in common encounter situations
Vessel hierarchy
Day Skipper exam focus: Power, sail, fishing, NUC, RAM, constrained by draught
Lights and shapes
Day Skipper exam focus: Identify vessel type and status by day or night
Sound and light signals
Day Skipper exam focus: Restricted visibility and manoeuvring signals
| Rule / part | Topic | Day Skipper exam focus |
|---|---|---|
| Rule 5 | Look-out | Sight, hearing, radar, AIS, and all available means |
| Rule 7 | Risk of collision | Constant bearing, decreasing range means danger |
| Rule 8 | Action to avoid collision | Act early, positively, and obviously |
| Rules 12-15 | Sailing, overtaking, head-on, crossing | Who gives way in common encounter situations |
| Rule 18 | Vessel hierarchy | Power, sail, fishing, NUC, RAM, constrained by draught |
| Part C | Lights and shapes | Identify vessel type and status by day or night |
| Part D | Sound and light signals | Restricted visibility and manoeuvring signals |
Common mistakes
- Jumping straight to give-way rules before checking risk of collision.
- Thinking the stand-on vessel can ignore the developing situation.
Quick practice check
Try a few questions before you move into the full module.
1. Two sailing vessels are approaching each other. Vessel A is on port tack, Vessel B is on starboard tack. Who gives way?
2. Two power-driven vessels are meeting head-on. What action should both take?
3. A sailing vessel is overtaking a power-driven vessel. Who gives way?
4. What is the most reliable method to determine risk of collision?
5. According to Rule 5, a proper look-out must be maintained using which means?
Common questions
What does COLREGs stand for?
COLREGs stands for the International Regulations for Preventing Collisions at Sea. They are also known as IRPCS.
Is it COLREG or COLREGs?
The regulations are normally referred to as COLREGs, but people often search for COLREG in the singular. Both refer to the collision regulations at sea.
Which COLREGs rules are most important for Day Skipper?
Day Skipper candidates need especially strong knowledge of the steering and sailing rules, including Rules 5, 7, 8, 9, 10, and 12-19.
Do COLREGs apply to sailing yachts?
Yes. COLREGs apply to all vessels, including sailing yachts. A sailing yacht using its engine is treated as a power-driven vessel.
Keep revising this topic
Last reviewed: 22 June 2026 by Day Skipper Revision
Build COLREGs confidence
The full COLREGs module breaks the rules into situations, vessel responsibilities, lights, shapes, and practical quiz feedback.