COLREG 1972 · rule 18 of 38
EnglishEN

Rule 18. Responsibilities between vessels

The order from the top down. Each gives way to everyone above her:

Part of the convention When you can see each other

The order from the top down. Each gives way to everyone above her:

  • A vessel not under command.
  • A vessel restricted in her ability to manoeuvre.
  • A vessel engaged in fishing (which gives way so far as possible).
  • A sailing vessel.
  • A power-driven vessel: she gives way to all of the above.
  • Separately: any vessel other than the first two shall, if the circumstances of the case admit, avoid impeding the safe passage of a vessel constrained by her draught, showing three all-round reds or a cylinder. That vessel must herself navigate with particular caution.
  • A seaplane on the water keeps well clear of all vessels. A WIG craft taking off, landing and in flight near the surface keeps well clear of all vessels; on the water she is an ordinary power-driven vessel.
At sea it looks like this

The bridge mnemonic: cannot, will not, fisher, sail, power. But rules 9, 10 and 13 override this order: in a channel and in a traffic lane a sailing vessel and a fishing vessel must not impede a big ship, and the overtaking vessel always keeps clear.

The rule says«Except where Rules 9, 10 and 13 otherwise require…»

Check yourself

Give the order of responsibilities under rule 18, top down.

Not under command, restricted in ability to manoeuvre, engaged in fishing, sailing, power-driven. Separately: all but the first two avoid impeding a vessel constrained by her draught.

Rule 18. Mnemonic: cannot, will not, fisher, sail, power.

Which wins: the order of rule 18, or the rules on channels, lanes and overtaking?

Rules 9, 10 and 13 win. In a channel and a traffic lane a sailing or fishing vessel must not impede a big ship, and the overtaking vessel always keeps clear.

The opening words of rule 18.

A seaplane on the water and a WIG craft in flight near the surface: how do they act?

Both keep well clear of all vessels and avoid impeding their navigation. On the water the WIG craft is an ordinary power-driven vessel.

Rule 18 (e), (f).

Part of the convention: When you can see each other