VHF Guide

VHF Communication Essentials

• Hailing: Everyone should be monitoring VHF 16; in Mexico most cruisers also monitor VHF 22A. Try hailing other yachts on either one. When hailing, be sure to mention what channel you are on if it is not 16 — radios can scan multiple channels.
• Selecting working channels: If you hail on Channel 16, moving "up one" to Channel 17 is a low-power channel, meaning it will fail over long distances; pick a channel supporting high power instead. Hailing on Channel 22 allows you to shift up (high power) or down (low power) one channel, though frequencies 24 through 28 are restricted. If adjacent channels are congested, scan further up or down the dial. Other popular channels are 68, 69, 72.
• Managing power ranges: Channel 67 is low-power (ideal for nearby vessels) while Channel 69 is high-power, but Channel 70 is blocked for digital selective calling only; channels 71 through 74 remain available at high power.
• Frequency propagation: Higher-numbered VHF channels typically achieve greater transmission range than lower-numbered ones.

Radio Settings & Troubleshooting

• Fixing transmission blocks: If you can clearly receive on Channel 18 or 22 but cannot transmit, your marine radio is likely set to International mode instead of USA mode.
• Checking hardware first: Before repeatedly hailing an unresponsive vessel, verify your squelch and volume knobs are adjusted correctly.
• Utilizing DSC technology: Configure your Digital Selective Calling (DSC) and print your MMSI number on your boat cards for direct hailing. Because busy anchorages often prompt cruisers to turn down their radio volume, DSC features will still audibly "ring" through the noise.
• Silencing anchor alarms: The most common false alarm in anchorages is a VHF radio equipped with AIS but lacking a GPS fix, which triggers a repetitive warning beep every four hours.

Net Etiquette

• Participating in radio nets: When joining a scheduled net, state your boat name clearly once and wait to be formally recognized by the net controller before speaking further.

Examples

Vessel Volare hailing vessel Linger Longer on 22A: