🔍 Key Concepts

• VHF (Very High Frequency) signals and how they travel • The meaning of line-of-sight in radio communication • Effect of antenna height versus transmitter power (watts) on range

💭 Think About

• Think about whether VHF signals bend around the earth like low-frequency radio, or if they travel mostly straight until blocked. • Ask yourself what limits how far two vessels can hear each other: is it the loudness (power) of the signal, or whether the antennas can "see" each other over the horizon? • Consider how raising an antenna changes the distance to the radio horizon compared to simply increasing wattage.

✅ Before You Answer

• Verify how VHF waves propagate over the sea surface (do they follow the curvature of the earth or not?). • Compare how antenna height affects the distance to the horizon versus how much extra distance more transmitter power can realistically add. • Check which option directly relates to VHF being a straight‑line / line‑of‑sight system rather than about sound, density of air, or absorption by seawater.