🔍 Key Concepts

• VHF radiotelephone operating modes on ship stations • Difference between simplex and duplex operation • Typical use of non-distress routine calling between ship stations

💭 Think About

• Ask yourself: when two ships talk directly to each other on a single working channel, do they usually both transmit and receive on the same frequency or on different paired frequencies? • Think about which mode (simplex or duplex) is normally used between a ship and a coast station, and which is used between two ship stations. • Consider whether choosing a specific channel number or choosing an operating mode makes more sense as a general ‘menu choice’ when initiating a routine call to another ship.

✅ Before You Answer

• Verify which mode is defined as one frequency used alternately for transmit and receive. • Verify which mode is defined as paired frequencies, one for transmit and one for receive. • Check which of the listed options are channel numbers and which are operating modes, and which one is normally associated with ship-to-ship VHF calling.