Sharing the waterways: right of way, navigation lights and sound signals
873 words · checked 2026-10-03 · Free
Key terms
| Term | Meaning |
|---|---|
| Bow / stern | Front / back of the boat |
| Port / starboard | Left / right side when facing the bow |
| Power-driven vessel | Any vessel propelled by machinery - including a sailboat using its motor |
| Sailing vessel | Under sail only, engine not in use |
| Give-way vessel | Must take early and substantial action to keep well clear |
| Stand-on vessel | Keeps its course and speed - but must act if the give-way vessel does not |
| Underway | Not at anchor, made fast to shore or aground |
| Restricted visibility | Fog, mist, heavy rain, snow, smoke |
General duties
- Lookout (Rule 5): keep a proper lookout by sight and hearing at all times.
- Safe speed (Rule 6): consider visibility, traffic density, manoeuvrability, wind, waves and current, and navigational hazards - be able to stop in time.
- Risk of collision (Rule 7): if the compass bearing of an approaching vessel does not change appreciably, risk of collision exists.
- Action to avoid collision (Rule 8): early, large and obvious - alter course and/or slow down.
- Narrow channels (Rule 9): keep to the starboard side; small boats (under 20 m) and sailing vessels must not impede larger vessels that can navigate only within the channel.
Key fact: No vessel ever has an absolute "right of way". Every operator must do whatever is needed to avoid a collision.
Who gives way? (power-driven vessels)
| Situation | Rule |
|---|---|
| Head-on (Rule 14) | Both vessels alter course to starboard and pass port-to-port |
| Crossing (Rule 15) | The vessel that has the other on its own starboard side gives way and should avoid crossing ahead of it. Think: the vessel on your right (starboard) has the right of way |
| Overtaking (Rule 13) | The overtaking vessel always keeps out of the way - whatever type it is - until it is past and clear |
Responsibilities between types (Rule 18)
Except when overtaking, a power-driven vessel gives way to:
- a vessel not under command (e.g. engine failure);
- a vessel restricted in its ability to manoeuvre (e.g. dredging, towing);
- a vessel engaged in fishing with nets or trawls (not trolling lines);
- a sailing vessel.
A sailing vessel gives way to vessels not under command, restricted in ability to manoeuvre and engaged in fishing. Human-powered craft (canoes, kayaks) are hard to see - all boaters should give them room, and paddlers should avoid shipping lanes.
Sailing vessels meeting each other (Rule 12)
- Wind on different sides: the vessel with the wind on its port side gives way.
- Wind on the same side: the windward vessel gives way to the leeward vessel.
Navigation lights (Rules 20-25)
Required from sunset to sunrise and in restricted visibility.
| Light | Colour / arc |
|---|---|
| Sidelights | Red on port, green on starboard, each 112.5° (from dead ahead to 22.5° abaft the beam) |
| Sternlight | White, 135° facing aft |
| Masthead light | White, 225° facing forward, above the sidelights |
| All-round light | White, 360° |
| Vessel | Lights |
|---|---|
| Power-driven, under 12 m | Sidelights + masthead light + sternlight, or sidelights + all-round white light |
| Power-driven, under 7 m with max speed ≤ 7 knots | All-round white light (sidelights if practicable) |
| Sailing vessel under sail | Sidelights + sternlight (under 20 m: may combine in one masthead tricolour); no masthead light unless motoring |
| Vessel under oars / paddles | May show sail lights, or have a white flashlight or lantern ready to show in time |
| At anchor (under 50 m) | One all-round white light |
Reading lights at night: see red and green together - a boat is coming straight at you; see only green - you are on its starboard side (it is the give-way vessel if crossing); see only red - you are on its port side, so you give way; see only white - you are probably overtaking it.
Sound signals (Rules 32-35)
- Short blast about 1 second; prolonged blast 4-6 seconds.
| Signal (vessels in sight) | Meaning |
|---|---|
| 1 short | "I am altering course to starboard" |
| 2 short | "I am altering course to port" |
| 3 short | "I am operating astern propulsion" (reversing) |
| 5 or more short | Danger / doubt - "I don't understand your intentions" |
| In restricted visibility | Signal |
|---|---|
| Power-driven, making way | 1 prolonged at intervals of not more than 2 minutes |
| Power-driven, underway but stopped | 2 prolonged every 2 minutes |
| Sailing, fishing, restricted, not under command | 1 prolonged + 2 short every 2 minutes |
Other waterway users
- Slow down and keep clear of divers (red flag with white diagonal stripe, or the blue-and-white "A" flag), swimmers, anglers, paddlers and docks.
- You are responsible for your wake - and any damage it causes.
- Large commercial ships cannot stop or turn quickly and have blind spots ahead; stay well clear of shipping channels and never cross close ahead.
- Locks and bridges: follow lockmaster instructions; enter slowly (no faster than 10 km/h).
Quick review
- Two power boats meet head-on. What do both do? (Alter course to starboard.)
- In a crossing situation, which boat gives way? (The one that has the other on its starboard side.)
- At night you see only a red light ahead. What does it mean? (You see the other boat's port side - you give way.)
- What do five short blasts mean? (Danger/doubt.)
- Which vessel keeps clear when overtaking? (The overtaking vessel, always.)