Digital Selective Calling (DSC)

VHF Marine Radio Protocols

For Example

The vessel Corsair calling the vessel Vagabond:

Corsair: “Vagabond, this is Corsair (station license number call sign).”

Vagabond: “Corsair, this is Vagabond. Over.”

Corsair: “Vagabond go to working Channel 68. Over.”

Both parties switch over to the agreed upon working channel....

Corsair: “Vagabond I need to talk to you about... Over.”

Vagabond: “Corsair in answer to your question about... Over.”

Corsair: “Vagabond, thanks for the information about... (call sign and out).”

After each transmission, say “OVER” and release the microphone Push to Talk (PTT) button. This confirms that the transmission has ended. When all communication with the other vessel is totally completed, end the message by stating your call sign and the word “OUT.” Remember, it is not necessary to state your call sign with each transmission, only at the beginning and end of the message.

NOTE

For best sound quality at the shore station or other vessel receiving your call, hold the microphone/speaker at least 2 in. (51 mm) from your mouth and slightly off to one (1) side. Speak in a normal tone of voice.

Digital Selective Calling (DSC)

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Digital selective calling is a semi-automated system for establishing a radio call. It has been designed by the International Maritime Organization (IMO) as an international standard for VHF, MF, and HF calls and is part of the Global Maritime Distress and Safety System (GMDSS).

DSC will eventually replace aural (listening) watches on distress frequencies and will be used to announce routine and urgent maritime safety information broadcasts. Until DSC is fully implemented, it is still necessary to maintain a listening watch on Channel 16.

The DSC system allows mariners to instantly send a distress call with GPS position coordinates (requires a GPS receiver to be connected to the radio) to the Coast Guard and other vessels within range of the transmission.

DSC also allows mariners to initiate and receive distress, urgent, safety, routine, position request, position send, and group calls between vessels equipped with DSC capable radios.

 

Maritime Mobile

 

 

Service Identity (MMSI)

 

VHF Marine Radio Protocols

 

 

 

Maritime Mobile Service Identity (MMSI)

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The MMSI Number Is Available In The U.S.A. From Any Of Two (2) Sources:

■Sea Tow International: 1-631-765-3660 – www.seatow.com

■BoatU.S.: 1-800-563-1536 – www.boatus.com/mmsi

An MMSI is a nine (9) digit number used on a marine radio capable of using digital selective calling (DSC). It is used to selectively call other vessels or shore stations and is similar to a telephone number.

For your CobraMarine™ radio to operate in the DSC mode, you must enter your maritime mobile service identity (MMSI) number. See page 41 for instructions on how to enter it.

In Canada, Contact:

■Industry Canada Spectrum Management Office (only available on the Internet): http://strategis.ic.gc.ca/epic/internet/insmt-gst.nsf/vwGeneratedInterE/sf01742e.html

To Obtain An MMSI Number Outside The U.S.A.:

Users can obtain an MMSI from their country’s telecommunications authority or ship registry. This may involve amending or obtaining a ship station license.

WARNING

This equipment is designed to generate a digital maritime distress and safety signal to facilitate search and rescue. To be effective as a safety device, this equipment must be used only within communication range of a shore-based VHF marine channel to distress and safety watch system. The range of the signal may vary, but under normal conditions should be approximately 20 nautical miles.

 

8 English

Nothing Comes Close to a Cobra® 9

 

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Cobra Electronics MR F75-D owner manual Digital Selective Calling DSC, Maritime Mobile Service Identity Mmsi
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MR F75-D specifications

Cobra Electronics has long been a name associated with reliable communication solutions, and the MR F75-D is no exception. This high-performance marine VHF radio is designed specifically for boaters, offering a blend of essential features, advanced technologies, and user-friendly characteristics that make it an excellent choice for both recreational and commercial marine applications.

One of the standout features of the MR F75-D is its Class D DSC (Digital Selective Calling) capability, which allows users to send distress calls and communicate with other vessels or coast guard stations at the push of a button. This increases safety on the water, as it provides an automated means to alert others in case of emergencies.

The radio operates seamlessly on the vital marine channels, ensuring that users have access to all the necessary frequencies for navigation and communication. With an impressive 25 watts of transmitting power, the MR F75-D provides extended range, ensuring that calls can be made even in challenging conditions.

The Cobra MR F75-D boasts an ergonomic design featuring a solid weather-resistant construction to withstand the harsh marine environment. Its large, easy-to-read backlit LCD display enhances readability in bright sunlight or low-light conditions, making it accessible under various circumstances.

Moreover, the radio includes a built-in NOAA weather radio with alerts. This feature keeps users informed about local weather conditions and forecasts, enabling them to make better decisions while out at sea. The option to scan channels and save favorites makes it easy to navigate through crowded frequencies to find the right communication line.

The MR F75-D is equipped with Dual Watch and Tri-Watch functions, allowing users to monitor two or three channels simultaneously. This increases the chances of receiving essential messages while on the water, providing greater peace of mind.

With a compact design, the MR F75-D can fit easily on most boats, while the intuitive controls enhance usability. The radio also supports external GPS connection, offering even better situational awareness.

In conclusion, the Cobra Electronics MR F75-D is a versatile, durable, and feature-rich marine VHF radio. With its DSC capabilities, NOAA weather notifications, and robust build, it proves to be an invaluable tool for safe and efficient marine communication, making it a top choice for any boating enthusiast.
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