May 28, 2024

5 min

Skills & Seamanship

How to Send a Distress Signal by VHF: A Guide for Sailors

VHF radio

For sailors, safety is paramount. Whether you’re navigating coastal waters or venturing far offshore, the ability to call for help quickly and effectively in an emergency can be the difference between life and death. For this reason, anyone heading to sea must know how to send a distress signal via VHF (Very High Frequency) radio. It is also an essential skill for anyone studying for an RYA course such as Day Skipper or an ASA course. This Rubicon 3 guide will tell you how.

Understanding the basics of VHF Radio

VHF is a radio frequency used for short-range communication. It operates on internationally recognized frequencies set aside for marine use, making it a vital tool for contacting nearby vessels, coast guards, and emergency services. Most marine VHF radios operate on frequencies between 156 and 174 MHz, providing reliable communication within a range of about 20-30 miles, depending on the height of the antenna and the surrounding environment.

The Importance of Knowing How to Send a Distress Signal

In an emergency at sea, every second counts. Knowing how to send a distress signal quickly and effectively ensures that help can be dispatched promptly.

Mayday vs. Pan Pan: Understanding the Difference in Meaning

It’s essential to know the difference between a Mayday call and a Pan-Pan call to communicate the severity of your situation accurately.

Mayday: This is the international distress signal used when there is a grave and imminent danger that threatens life or the vessel. Use Mayday when immediate assistance is required. Examples include:

  • Your vessel is sinking.
  • There’s a fire onboard.
  • A serious medical emergency where life is at risk.
  • Collision with another vessel causing severe damage.

Pan Pan: This signal is used when there is an urgent situation but no immediate danger to life or the vessel. It indicates that you need assistance, but it’s not a life-threatening emergency. Examples include:

  • Engine failure in a busy shipping lane.
  • Running aground without immediate risk of sinking.
  • Minor medical issues where immediate help is needed but not life-threatening.
  • Loss of steering in rough seas.

How to Send a Distress Signal Using VHF Radio

When sending a distress signal, it’s helpful to remember the acronym MIPDANIO, which outlines the essential information to include in your call:

  1. MAYDAY, MAYDAY, MAYDAY: The international distress signal indicates a life-threatening situation.
  2. Identity: State the name of your vessel three times.
  3. Position: Give your location in latitude and longitude, or describe your location relative to a known landmark.
  4. Distress: Clearly describe the nature of the emergency (e.g., fire, sinking, collision).
  5. Assistance: Specify the type of assistance required (e.g., medical aid, evacuation).
  6. Number of People on Board: Provide the number of people on your vessel.
  7. Information: Offer any additional information that could help rescuers, such as vessel description, weather conditions, or any injuries.
  8. Over: Conclude your message with “Over” and wait for a response.

Following this structured format ensures that you provide all necessary information concisely and clearly, facilitating a swift and effective response. Remember, you have to be in range of another VHF station. You can learn how to work out VHF range here.

Step-by-Step Distress Signal Procedure

  1. Tune to Channel 16: Channel 16 (156.8 MHz) is the international distress, safety, and calling frequency. All VHF radios are programmed to receive and transmit on this channel. In an emergency, switch your VHF radio to Channel 16.
  2. Transmit the Distress Call: Follow these steps to send a proper distress signal using the MIPDANIO format:
    • Press the push-to-talk (PTT) button and clearly state: “MAYDAY, MAYDAY, MAYDAY.”
    • After releasing the PTT button momentarily, press it again and state:
      • “This is your vessel name, your vessel name, your vessel name.”
      • Provide your position in latitude and longitude, or provide a landmark if the exact coordinates are not available.
      • Describe the nature of your distress (e.g., fire, sinking, collision).
      • Provide additional details that could assist rescuers, such as the number of people on board, the type of assistance needed, and any other pertinent information.
  3. Wait for a Response: After sending the distress call, release the PTT button and wait for a response. Rescuers or other vessels in the vicinity should respond to your call. If you do not receive a response within a minute repeat the distress call.

Other Considerations

  • Digital Selective Calling (DSC): Modern VHF radios are equipped with DSC, which allows for automated distress calls. Ensure your radio is connected to a GPS to transmit your exact location automatically. Activating the distress button on a DSC-equipped radio sends an automated digital distress alert to all DSC-equipped vessels and shore stations within range. You should still follow this up with a spoken emergency call as detailed above.
  • Maintain Your Equipment: Check your VHF radio once a season to ensure it is in good working order. Check the antenna connections, and the GPS / DSC connection and perform a radio check with other vessels or marine stations.

Printable Reference Guide

Add in your vessel details, then print the section below, laminate it, and post by your VHF station


  1. Tune to Channel 16 (156.8 MHz)
  2. Press the Push-to-Talk (PTT) Button
  3. Say Clearly:
  4. Release PTT, then Press Again and Say:
    • “This is your vessel name, your vessel name, your vessel name”
  5. Provide Your Position:
    • Latitude and Longitude OR
    • Distance and Direction from a Known Point
  6. Describe the Emergency:
    • Nature of distress (e.g., fire, sinking, collision)
  7. State the Assistance Needed:
    • Type of help required (e.g., medical, evacuation)
  8. Give Additional Details:
    • Number of people on board
    • Any other relevant information
  9. End with:
    • “Over”


The ability to send a distress signal via VHF is a critical skill for every sailor. Practice and proper equipment maintenance ensure you are prepared to communicate effectively in an emergency. Remember the MIPDANIO acronym to ensure you provide all necessary information in a structured manner. Your knowledge and readiness can save lives—yours and others—on the unpredictable waters of the open sea. Stay safe, and happy sailing!

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