CRITICAL

Emergency Communications

VHF, SSB, and Satellite communication protocols for emergency situations in Prince William Sound.

Emergency Communications

Maritime communication is critical for safety in Prince William Sound. Because the surrounding geography is mountainous and steep, radio and telephone signals are frequently obstructed.

Marine VHF Radio

  • Monitor VHF Channel 16 at all times while underway.
  • Keep VHF Channel 16 strictly reserved for distress alerts and initial calling. Once you establish contact, move to an active working channel (such as 68, 69, 71, or 72) to complete your conversation.
  • Signal Blockage: High mountains block VHF signals (which travel by line-of-sight). If you cannot transmit, try moving your vessel to an open area or seek higher ground if using a handheld radio.
  • Relaying Distress: If you receive a distress call that appears unacknowledged, maintain a listening watch, record the information, and follow applicable Coast Guard/FCC distress-relay procedures. Do not interfere with ongoing distress traffic.

Digital Selective Calling (DSC) & MMSI

Modern marine VHF radios include Digital Selective Calling (DSC) functions.

  • The Distress Button: A properly programmed DSC radio with a valid MMSI and current GPS input can transmit a digital distress alert containing position information. Transmission and receipt are not guaranteed (e.g., if GPS connection is lost, MMSI programming is incomplete, or receiving stations are out of range).
  • MMSI Number Registration: To enable DSC functions, you must obtain a 9-digit Maritime Mobile Service Identity (MMSI) number and program it into your radio unit.
  • GPS Integration: Ensure your VHF radio is connected to your onboard GPS receiver so your exact coordinates are included in any distress alerts.

How to Transmit a MAYDAY Call

Only use the word MAYDAY if your vessel or passengers are in immediate danger of loss of life or sinking.

  1. Switch to VHF Channel 16.
  2. Clearly state: “MAYDAY, MAYDAY, MAYDAY.”
  3. State: “This is the vessel [Vessel Name], [Vessel Name], [Vessel Name].”
  4. Provide your location (GPS coordinates, or distance/bearing from a known island or point).
  5. State the type of emergency (e.g., vessel on fire, taking on water, medical crisis).
  6. Give the total number of people on board and details of any injuries.
  7. Listen for a response. If you hear none, repeat the distress transmission.

Information Checklist for Search & Rescue:

  • Vessel description: length, propulsion type, colors of hull/superstructure, registration numbers.
  • Weather on scene: wind strength and direction, wave heights, visibility.
  • Safety equipment carried: liferafts, survival suits, emergency beacons.

📡 Standard VHF MAYDAY Transmission Script

If you are in grave and imminent danger, do not delay. Switch your VHF radio to Channel 16, select high power (25 watts), press the Push-to-Talk button, and read this standard script slowly and clearly. Repeat it three times if possible:

MAYDAY, MAYDAY, MAYDAY.
THIS IS [Vessel Name], [Vessel Name], [Vessel Name].
[Call Sign or Registration Number].

MAYDAY, [Vessel Name].
POSITION: [Coordinates, Lat/Long, or distance/bearing from a known landmark].
NATURE OF DISTRESS: [e.g., Sinking, Onboard fire, Severe medical emergency].
PERSONS ON BOARD: [Number of souls on board].
VESSEL DESCRIPTION: [Length, hull color, superstructure, deck features].

WE REQUIRE IMMEDIATE ASSISTANCE.
OVER.

[!IMPORTANT] Distress Priority: Speak slowly and clearly. If you do not receive an immediate response from the Coast Guard or a nearby vessel, repeat the transmission at short intervals. Keep your radio on VHF CH 16 to monitor for hails.

Alternative Communication Tools

  • Single Side Band (SSB): The U.S. Coast Guard monitors specific HF voice frequencies for long-range communication. Frequencies and watchkeeping services are subject to change. Verify the current monitored voice frequencies directly on the official U.S. Coast Guard HF Frequency Information Portal.
  • Phones: Cellular coverage is poor or nonexistent in most parts of Prince William Sound. Do not rely on mobile cell signal for safety. If an active cellular connection is available, you may dial Sector Anchorage Command Center directly at 907-428-4100 or call 911 if within range. Always provide your phone number and location immediately when connected in case the call drops. Satellite phones are a reliable option but do not connect directly to local direction-finding equipment. (Last verified: July 2026)
  • Satellite Beacons: Carry EPIRBs or PLBs on your vessel and keep them registered. Satellite messaging units (such as Garmin inReach) are highly useful for communicating status and tracking details when out of radio range.