🔍 Key Concepts

• VHF-FM radiotelephone procedures for ship-to-shore calls • The difference between voice traffic, signaling tones, and telephone-style busy signals • How you determine if a VHF working channel is already in use before transmitting

💭 Think About

• When you monitor a VHF working channel before calling, what specific sound tells you that someone is already using it? • Do VHF marine channels normally produce a telephone-style "busy signal," or is that something you associate more with landline telephones? • Are signaling tones (like call set-up or alert tones) always an indication that the channel is busy with a conversation, or can they occur briefly without continuous use of the channel?

✅ Before You Answer

• Verify what you actually hear on a busy marine VHF working channel during normal operation • Think about which of the options is not typically part of standard VHF-FM audio during regular marine communications • Confirm whether "busy signal" in this context really exists on VHF, or if it mainly applies to telephone networks rather than radio channels