Module 5 - COLREGs

Rule 7 — Risk of Collision

You must use all available means to determine if a risk of collision exists. If there is any doubt, assume it does exist.

The most reliable technique is compass bearings: if the bearing of an approaching vessel does not change appreciably, a risk of collision exists. This is called a 'constant bearing, decreasing range' (CBDR) situation.

  • If in doubt, risk of collision EXISTS
  • Constant bearing + decreasing range = collision risk
  • Use compass bearings to assess risk

Watch for this: Take a series of compass bearings on an approaching vessel. If the bearing stays roughly the same but the vessel is getting closer, you are on a collision course.

Apply Rule 7 to complete encounters

The COLREGs module links lookout, safe speed, risk assessment, avoiding action and vessel responsibilities.

Practice COLREGs
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