Who has the right of way at sea?
Strictly speaking, nobody: the sea has no road-style right of way. The COLREG knows give-way vessels and stand-on vessels, and who is which is set by the ladder of Rule 18, with three exceptions that can beat it. This page is the whole logic in one place.
The pecking order (Rule 18)
An approximate hierarchy of duties, not an absolute right of way: before you lean on it, check the exceptions below. Click a rung to see that vessel’s lights in the trainer.
- 1 Vessel not under command Two red all-round lights in a vertical line
- 2 Vessel restricted in her ability to manoeuvre Red, white, red all-round lights in a vertical line
- 3 Vessel engaged in fishing (includes trawling (Rule 26)) Red over white, both all-round
- 4 Sailing vessel Sidelights and sternlight only, no masthead light
- 5 Power-driven vessel White masthead light(s), green and red sidelights, white sternlight
A vessel constrained by her draught holds no ordinary rung on this ladder (Rules 18d and 28): other vessels should, if the circumstances of the case admit, avoid impeding her safe passage, and she herself navigates with particular caution. Full text: Rule 18.
The exceptions that beat the ladder
- Rule 13: The overtaking vessel keeps out of the way of the vessel overtaken. Always, whatever the types involved.
- Rule 9: In a narrow channel a small vessel (under 20 m), a sailing vessel and a vessel fishing do not impede a vessel confined to the channel.
- Rule 10: In a traffic separation scheme a vessel fishing does not impede a vessel following a lane, and a vessel under 20 m or a sailing vessel does not impede the safe passage of a power-driven vessel following a lane.
- Rule 28: Do not impede the safe passage of a vessel constrained by her draught (Rule 18d).
This is where the most common myth dies: "sail always has right of way". Not true. A sailing vessel gives way to everything above her on the ladder, does not impede in a narrow channel or a traffic lane, and when she overtakes, she gives way to whoever she is overtaking.
Two power-driven vessels: the three situations
In fog there is no ladder
Rules 12-18 apply only to vessels in sight of one another. When you hold the other ship on radar alone, there is no give-way and no stand-on vessel: each assesses the risk for herself and manoeuvres under Rule 19. The fog signals tell you what the other vessel is, but they neither replace visual contact nor create the roles.
This page covers the sea (the COLREG). Inland waters have their own, different rules. The commentary is our own: when in doubt, the wording of the Convention decides.