Module 5 - COLREGs

Rule 18 — Responsibilities Between Vessels

Rule 18 sets responsibilities between vessel types and statuses. It is a practical guide to who should keep clear in normal sighted encounters, not an absolute right-of-way ladder.

Power-driven and sailing vessels have specific keep-clear duties towards vessels engaged in fishing, vessels not under command (NUC), and vessels restricted in ability to manoeuvre (RAM). A vessel constrained by her draught displays special signals and must navigate with particular caution; other vessels should avoid impeding her where depth, the fairway, or the channel limits her movement. Remember: a sailing vessel using its engine is a power-driven vessel.

  • Rule 18 sets keep-clear duties by vessel status and manoeuvrability
  • Avoid impeding vessels limited by channel, fairway, or draught constraints
  • A sailing vessel with engine running is POWER-DRIVEN
  • Rule 13 (overtaking) always applies regardless of type

Watch for this: Use Rule 18 as a decision aid, then keep Rule 2 in mind: both vessels still share responsibility for avoiding collision.

Practice the full encounter sequence

The complete module tests overtaking, crossing, restricted visibility, lights, shapes and responsibilities together.