Skippers traveling the U.S. inland waterways use their VHF radios almost every day to contact other vessels and bridgetenders, make reservations at marinas, arrange to pass other vessels safely and conduct other business. Waterway Guide has put together the following information to help remove any confusion as to what frequency should be dialed in to call bridges, marinas, commercial ships or your friend anchored down the creek.

Remember to use low power (1 watt) for your radio transmission whenever possible. If you are within a couple of miles of the responding station (bridge, marina or other craft), there is no need to broadcast at 25 watts and disturb the transmissions of others 25 miles away.

Channel Usage Tips

• VHF Channel 16 (156.8 MHz) is by far the most important frequency on the VHF-FM band. VHF Channel 16 is the inter­national distress, safety and calling frequency.

• If you have a VHF radio on your boat, Federal Communications Commission (FCC) regulations require that you maintain a watch on either VHF Channel 09 or 16 whenever you are underway and the radio is not being used to communicate on another channel. Since the Coast Guard does not have the capability of announcing an urgent marine information broadcast or weather warning on VHF Channel 09, it recommends that boaters remain tuned to and use VHF Channel 16.

• Recreational craft typically communicate on VHF Channels 68, 69, 71, 72 or 78A. Whenever possible, avoid calling on VHF Channel 16 altogether by prearranging initial contact directly on one of these channels. No transmissions should last longer than 3 minutes.

• The Coast Guard's main working VHF Channel is 22A, and both emergency and non-emergency calls generally are switched to it in order to keep VHF Channel 16 clear. Calling the Coast Guard for a radio check on VHF Channel 16 is prohibited.

• Radio-equipped bridges on the Atlantic ICW use VHF Channel 09 with a few exceptions.

• The Bridge-to-Bridge Radio Telephone Act requires many commercial vessels, including dredges and tugboats, to monitor VHF Channel 13. VHF Channel 13 is also the frequency used by bridges in several states.

VHF Channels

09: Used for radio checks and hailing other stations (boats, shoreside operations). Also used to communicate with drawbridges in the State of Florida.

13: Used to contact and communicate with commercial vessels, military ships and drawbridges. Bridges in several states monitor VHF Channel 13.

16: Emergency use only! May be used to hail other vessels, but once contact is made, conversation should be immediately switched to a working (68, 69, 71, 72, 78A) VHF channel.

22: Used for U.S. Coast Guard safety, navigation and Sécurité communications.

68, 69, 71, 72 & 78A: Used primarily for recreational ship-to-ship and 
ship-to-shore communications.

Distress Calls

• MAYDAY: The distress signal "MAYDAY" is used to indicate that a vessel is threatened by grave and imminent danger and requests immediate assistance.
• PAN PAN: The urgency signal "PAN PAN" is used when the safety of the ship or person is in jeopardy.
• SÉCURITÉ: The safety signal "SÉCURITÉ" is used for messages about the safety of navigation or important weather warnings.

VHF Channel 16 is the distress call frequency. The codeword "MAYDAY" is the international alert signal of a life-threatening situation at sea. After a MAYDAY message is broadcast, VHF Channel 16 must be kept free of all traffic, other than those directly involved in the rescue situation, until the rescue has been completed.

If you hear a MAYDAY message and no one else is responding, it is your duty to step in to answer the call, relay it to the nearest rescue organization and get to the scene to help. Remember, a MAYDAY distress call can only be used when life is threatened. For example, if you have run on the rocks but no one is going to lose their life, that is NOT a MAYDAY situation.

How to Make a Distress Call

MAYDAY! MAYDAY! MAYDAY!

This is: Give your vessel name and call sign.

Our position is: Read it off the GPS, or give it as something like "two miles southwest of Royal Island." (Your rescuers must be able to find you!)

We are: Describe what's happening (e.g., on fire/hit a reef/sinking).

We have: Report how many people are on board.

At this time we are: Say what you're doing about the crisis (e.g., standing by/abandoning ship).

For identification we are: Describe your boat: type, length, color, etc. (so your rescuers can more readily identify you).

We have: List safety equipment you have (e.g., flares/smoke/ocean dye markers/EPIRB).

We will keep watch on Channel 16 as long as we can.

Note: The Coast Guard has asked the FCC to eliminate provisions for using VHF Channel 09 as an alternative calling frequency to VHF Channel 16 when it eliminates watch-keeping on VHF Channel 16 by compulsory-equipped vessels. Stay tuned for updates.