Everyone needs to know proper radio procedures and what to do in an emergency - even when there isn’t one.

Your marine VHF radio is obviously your only link to the land while sailing and a very important piece of safety equipment,   whose use is regulated by local and international law. When used properly, it provides a critical communication link to potential rescuers in an emergency and access to weather forecasts, navigation alerts, and notices to mariners. It can be also used to communicate with passing  ships .
• VHF radios are not toys. Don’t clog important channels with idle chatter, and never, never make a false Mayday call. You are putting lives at risk, and you can be prosecuted.
• Always monitor channel 16. If you receive a distress call, record it and your position in your log, and be prepared to render assistance if at all possible.
• When sending a message, press the handset’s push-to-talk (PTT) button, and speak slowly and clearly into the microphone. Use the phonetic alphabet to spell out important information, and always confirm a received message.
• Don’t attempt to hail another user while the hailing channel is active. Breaking into an active radio transmission is bad VHF etiquette at best and could possibly interfere with an emergency transmission. When hailing another boat (on channel 9 or 16), establish contact and then quickly switch to an established working channel.
• Never use profanity, always transmit using minimum power, keep conversations as brief as possible, and remember that most VHF calls are audible to any radio in range that is monitoring your channel. So watch what you say; you never know who is listening.
• When you go shopping for a VHF, make sure that it has the proper NMEA connections to allow it to interface easily with your GPS.
• Last but not least, never say "over and out" at the end of a transmission. "Over" means "over to you"; "out" means you are ending the transmission. When you’ve completed your conversation, just say "out." Same holds true for "roger, wilco." Nothing says VHF rookie like "roger, wilco" followed by "over and out."
 
HOW TO USE YOUR RADIO
1.  Supervising Station
When tuned to channel 16, “Radio Olympia” is the name of the Coast Guard station in Greece.  Calling “Radio Olympia” you can ask for weather forecast, medicine support, or a MayDay. To make a call
1. Press the PTT and say “Radio Olympia” – “Radio Olympia” (up to three times)
2. “This is sail boat Barbara” (up to three times)
3. “We would like a weather forecast for Saronic golf, Over”
If you have no reply, you call again three minutes latter.

 2. Making a Mayday Call
MAYDAY is a request for immediate assistance in an imminent life-threatening situation. If you hear a Mayday call, listen—do not transmit. Determine if you are in a position to assist. If not, maintain radio silence and monitor the call.
To make a Mayday call, tune to channel 16 and follow the instructions below. Remain calm, and speak clearly. Remember that calling MayDay means that  people and boat are in danger, and the situation is out of control and you request for resque.
1.  Press the PPT and saying, "Mayday, Mayday, Mayday. This is (name of your boat repeated three times)."
2. Repeat "Mayday, this is (your boat name)" one more time.

3.  Report your position as accurately as possible.
4. Report the nature of the emergency.
5. Report the kind of assistance required.
6. Report the number of people aboard and the condition of any injured.
7. Describe the boat (length, design, color, distinguishing marks) and her present condition and seaworthiness. The message should not exceed one minute.
8. If there is no response, repeat the entire message. If there is still no response, try another channel.

3. Making a Pan-Pan Call
PAN-PAN announces an emergency when a boat and/or people face a difficult situation but not in imminent danger. As with a Mayday call, listen to the pan-pan call, determine if you are in a position to assist, and keep radio silence if you are not.
To make a “pan-Pan” call, follow the same procedure but substitute "Pan-Pan" (pronounced pahn-pahn) for "Mayday."
Such a situation could be a fire on board, a man over board etc

4. Making a Securite Call
SÉCURITÉ (see-cure-i-tay) is the signal that navigation information or weather warnings will be broadcast.
In case you wish to inform other ships or “Radio Olympia”  about a general danger concerning navigation  in your area (i.e. afloating object) , follow the same procedure but substitute "Securite" (pronounced secureitee) for "Mayday."

5. Important Channels
CHANNEL 16 is the distress, safety, and calling (hailing) frequency that the Greek Coast Guard monitors continuously. All vessels equipped with a VHF must monitor channel 16 when underway and be prepared to assist in an emergency. Always initiate contact with the Coast Guard on channel 16; you'll be redirected to a working channel. Never request a radio check on 16.
CHANNELS 70, 76, 77 are auxiliary to channel 16 and GMDSS. It is prohibited to use them.
CHANNEL 86  is a weather forecast channel in Greek and English language.
CHANNEL 13 is the navigation/piloting channel. Locks and bridges monitor channel 13, and it must be used for navigation and piloting purposes only.
CHANNELS 8-11, 66-69, 71-74are common working channels. Switch to one of those for ship to ship communication.

 6. Phonetic Alphabet
 Clear communication is critical when sending emergency VHF messages. To avoid any confusion, use the phonetic alphabet to spell out important information, such as your boat name and the names of your crew. Below is the NATO/International phonetic alphabet.

 7. Hailing and Communication With Another Boat
 Correct hailing procedure is to state the name of the boat you are hailing (usually on channel 16), then the name of your boat, followed by "over." "Over" tells the other party you have finished speaking. This is important because if both radio operators transmit at the same time, neither will be heard. Only one party can speak at a time. Any other words—"yoo hoo" or "Is anybody out there?"—constitute incorrect procedure. Once you’ve established contact, switch to a working channel. Once you’ve switched to a working channel, say the name of the boat you are hailing followed by the name of your boat. At the end of your conversation, say your boat name and "out" or "out, (your boat’s name), returning to 16."

 
8. Digital Selective Calling (DSC)
DSC is a semiautomated method of establishing a radio call simply by pushing the distress button. When the DSC button is activated, the radio automatically sends a distress call with GPS position (when a GPS is connected to the transceiver) and the nature of the distress to the Coast Guard and other vessels within range of the transmission. It then scans the appropriate channels for a response. DSC also allows users to immediately receive distress, urgent, safety, routine, position requests, and group calls from other DSC-equipped transceivers within range. Every radio equipped with DSC must have a Maritime Mobile Service Identity (MMSI) number assigned to it. A radio’s MMSI is a unique nine-digit number (similar to a telephone number) that must be programmed into the radio and registered to operate the DSC functions..

 
9. to Make a DSC Distress Call
1. Lift the protective cover over the distress button and press and hold the button until the radio’s display shows that the call has been sent.
2. Once the message has been sent, the transceiver will sound an audible distress alarm.
3. The transceiver will automatically monitor channel 70 for a DSC acknowledgement and will also receive calls on channel 16.
4. If no DSC acknowledgement is received, the transceiver will repeat the distress call at four-minute intervals until acknowledgement is received.
5. When the DSC acknowledgement signal is received, an alarm sounds, channel 16 is automatically selected, and the radio’s LCD screen shows the MMSI of the responding transceiver.
6  If the Distress button was pushed in error, many radios will cancel a distress call when the Clr and then Ent buttons are pushed.