🔍 Key Concepts

• Special whistle signals used by U.S. Coast Guard icebreakers • Difference between normal COLREGS sound signals and icebreaking escort signals • How icebreakers communicate changes in escort status or movement to following ships

💭 Think About

• Think about what an icebreaker needs to tell the ships following close behind when it makes a significant change in its movement or situation • Ask yourself: is this signal more likely to mean a change in engine order, a change in spacing between ships, a change in speed through the ice, or that the icebreaker can no longer proceed? • Consider which option would be critical for safety for following vessels if they suddenly had to react to the icebreaker’s situation.

✅ Before You Answer

• Verify that this is not one of the standard COLREGS maneuvering signals (1 short, 2 short, 3 short, etc.) • Confirm that this is a special U.S. Coast Guard icebreaking signal, not a general international signal • Check which option best matches an icebreaker’s need to warn escorts of a serious limitation or stoppage in its ability to continue breaking ice.