🔍 Key Concepts

• Inland Rule 34 – Maneuvering and Warning Signals for overtaking in narrow channels • How radiotelephone agreements can affect whistle-signal requirements under Inland Rules • The specific meaning (or lack of meaning) of four short blasts on the whistle in the Inland Rules

💭 Think About

• Look up what sound signals are actually prescribed for overtaking another power‑driven vessel in a narrow channel Inland. Do any of those involve four short blasts? • Under Inland Rules, when two vessels reach a clear agreement by radiotelephone about how they will pass, what happens to the requirement to sound whistle signals? • The question uses the word "may". Are you being asked what you are required to do, or which options are legally permitted actions in this situation?

✅ Before You Answer

• Verify in 33 CFR 83.34(c) what whistle signals are used for overtaking in a narrow channel and what each pattern means. • Check 33 CFR 83.34(h) about when a radiotelephone agreement can replace whistle signals under Inland Rules. • Make sure each choice you keep is something the rules expressly allow, even if it is not always required in every overtaking situation.