• Anchoring & Mooring
  • Boat Anatomy
  • Boat Culture
  • Boat Equipment
  • Boat Safety
  • Boat Tech
  • Boat Types
  • Navigation
  • Propulsion
  • Sailing Techniques
No Result
View All Result
Sailing and Boating Guides, Features | The Bosun
No Result
View All Result
Sailing and Boating Guides, Features | The Bosun
No Result
View All Result
digital selective calling DSC

Digital Selective Calling (DSC) – A Comprehensive Guide

May 3, 2023
in Boat Tech
0

Digital Selective Calling (DSC) – A Comprehensive Guide

Digital Selective Calling (DSC) is a vital communication tool for enhancing sea safety, efficiency, and coordination. This comprehensive guide covers the main components of the DSC system, including VHF and MF/HF radios, the Global Maritime Distress and Safety System (GMDSS), and Maritime Mobile Service Identity (MMSI). 

We also delve into the features of DSC, such as selective calling, group calling, and automated distress alerting. Furthermore, we discuss how to obtain an MMSI, program your DSC radio, and properly use DSC in various situations. Finally, we explore DSC-compatible equipment and integration with other marine systems.

Key Takeaways

  • DSC enhances maritime safety and efficiency through selective calling, group calling, and automated distress alerting.
  • MMSI numbers, acting like phone numbers, allow direct communication between vessels.
  • DSC is a vital component of the Global Maritime Distress and Safety System (GMDSS).
  • Obtain an MMSI through national authorities or private organizations, then program it into your DSC radio.
  • Proper use of DSC is crucial for effective communication in routine, urgent, and distress situations.
  • Integrating DSC with marine equipment, such as GPS and AIS, enhances safety and communication capabilities.

Jump to...

Understanding the DSC Distress Alert and Calling System

Three main components of the DSC system work together to provide efficient and reliable communication at sea.

VHF and MF/HF radios

DSC is primarily used with VHF (Very High Frequency) radios, but it can also be used with MF (Medium Frequency) and HF (High Frequency) radios. These radios allow communication over different distances and are crucial for safety.

Global Maritime Distress and Safety System (GMDSS)

The GMDSS is an international system designed to improve maritime safety by ensuring effective communication between vessels and shore stations. DSC plays a vital role in the GMDSS by sending distress alerts and selective calling features.

Maritime Mobile Service Identity (MMSI)

An MMSI is a unique nine-digit number assigned to each boat. It acts like a phone number, allowing DSC-equipped radios to directly contact specific ships or groups of ships. MMSIs are crucial for efficient communication and safety at sea.

DSC frequency bands

DSC operates on specific bands, which are used to transmit and receive digital information. 

VHF (156.525 MHz) and Channel 70

VHF is the primary method used for DSC communication. Channel 70 (156.525 MHz) is dedicated exclusively to DSC, ensuring reliable and interference-free communication.

MF (2187.5 kHz)

MF is another used for DSC, particularly for longer-range communication. It can be beneficial in areas where VHF coverage is limited.

HF (4207.5, 6312, 8414.5, 12577, and 16804.5 kHz)

HF is used for long-range communication and is essential for boats sailing in remote areas. Several frequencies within the HF band are dedicated to DSC, ensuring that communication remains clear and reliable.

Features of DSC (Digital Selective Calling)

DSC provides several advanced communication features that help streamline and improve communication:

  1. Selective calling: With DSC, you can directly call specific boats using their MMSI numbers, just like dialling a phone number. This feature allows for efficient, private communication between boats.
  2. Group calling: DSC also enables group calling, allowing you to communicate with multiple vessels simultaneously. This is particularly useful for coordinating activities or sharing information with a fleet of boats.
  3. All ships calling: An all-ships call is a broadcast message sent to all boats within range. This can be used to share important safety or navigational information with nearby boats.
  4. Geographical calling: DSC allows you to target boats within a specific geographical area. This is useful for sharing local information or coordinating activities with nearby boats.

Automated DSC Distress Alerting

One of the key benefits of DSC is its automated distress alerting system, which significantly improves safety at sea:

  1. Distress button and priority handling: When pressed, the radios have a dedicated distress button that sends an automated alert. This alert is given priority, ensuring a rapid response from nearby boats and coast guard shore stations.
  2. Distress call format and content: The automated alert includes crucial information such as the boat’s MMSI, position, and nature of distress. This helps responders assess the situation and provide appropriate assistance.
  3. GPS integration and location data: The radios can be integrated with the craft’s GPS, ensuring accurate location data is included in the alerts. This allows for faster and more precise responses in emergencies.

Improved safety and efficiency

DSC offers several benefits that contribute to a safer and more efficient marine environment:

  1. Reduction in false alarms: DSC’s digital communication system reduces the risk of false alarms, ensuring that resources are focused on genuine emergencies.
  2. Faster response to distress situations: With automated alerts and accurate location data, DSC enables faster responses to emergencies, potentially saving lives and property.
  3. Better coordination among vessels: DSC’s selective calling and group calling features improve vessel coordination, enhancing safety and efficiency during boating activities.

VHF DSC RadioMMSI (Maritime Mobile Service Identity)

How to obtain an MMSI

An MMSI is a unique nine-digit number assigned to your vessel. To obtain one, you can register through either a national authority or a private organisation:

National authority registration

  1. In the United States, the Federal Communications Commission (FCC) issues MMSIs. You must apply for a Ship Radio Station License through the FCC’s Universal Licensing System (ULS) to obtain one. Once your application is approved, you’ll receive your number.
  2. In the United Kingdom, the Office of Communications (Ofcom) issues MMSIs. You can apply by registering your vessel’s radio equipment on the Ofcom website. After submitting your application, you’ll receive your number.
  3. In Australia, the Australian Maritime Safety Authority (AMSA) issues MMSIs. You’ll need to complete an application form on the AMSA website to obtain one. Once your application is processed, you’ll receive your number.

Private Organisation registration

Alternatively, you can obtain an MMSI through private organisations such as BoatUS, Sea Tow, or the U.S. Power Squadrons. These organisations can issue MMSIs for recreational vessels that do not require an FCC-issued Ship Radio Station License. Remember that MMSIs obtained through private organisations may not be valid for international travel.

Programming your DSC radio with your MMSI

Once you obtain an MMSI, you must program it into your radio. This process may vary slightly depending on your radio’s specific make and model, so always refer to the manufacturer’s instructions.

Entering MMSI and other information

To program your MMSI, access the radio’s menu system and look for an option related to MMSI or DSC setup. Enter your nine-digit number and any other required information, such as vessel name, call sign, or GPS data. Save the information and exit the menu.

Updating and changing MMSI information

If you need to update or change your MMSI information, you may be able to do so through your radio’s menu system. However, some radios may require a factory reset or a visit to a service centre to update the number. Always consult your radio’s manual or contact the manufacturer for guidance on updating your information.

Proper Use of the DSC Radio in Various Situations

In this section, we’ll discuss the appropriate use of Digital Selective Calling (DSC) in various situations, including routine communication, urgent and safety communication, and distress communication. Understanding the proper use of DSC will help ensure efficient and effective communication on the water.

Routine communication

For day-to-day communication, DSC provides several features to facilitate effective communication between vessels:

  1. Individual calling: Selective calling lets you contact a specific vessel directly by entering its MMSI number. This is useful for private conversations between two boats.
  2. Group calling: Group calling enables you to communicate with multiple vessels simultaneously by entering their MMSI numbers or a designated group ID. This is particularly helpful for coordinating activities or sharing information among a fleet of boats.
  3. Working channel and listening watch: Remember to switch to a working channel after establishing contact when using DSC for routine communication. This ensures the DSC channel (Channel 70) remains available for other users. Also, maintain a listening watch on the VHF to monitor incoming calls or important announcements.

Urgent and safety communication

For urgent or safety-related communication, DSC offers specific features to ensure that important information is communicated efficiently:

  1. Safety announcements: Safety announcements can be made using the “All Ships” call feature, which broadcasts a message to all vessels within range. This is useful for sharing important safety or navigational information with nearby boats.
  2. Urgency and routine calls: For less urgent situations that still require prompt attention, use the “Urgency” call feature. This sends a message to a specific vessel or group of boats, indicating the need for immediate assistance or action.

Distress communication

In emergencies, DSC provides a streamlined method for initiating and responding to emergency  alerts:

  1. Initiating an alert: Press the dedicated distress button on your DSC radio to create a distress alert. This sends an automated transmission, which includes your vessel’s MMSI, position, and the nature of the distress, to nearby ships and shore stations.
  2. Responding to a distress alert: If you receive a distress alert, ensure you are not in immediate danger. Then, if you can assist, acknowledge the alert and communicate with the vessel in distress using the working channels.
  3. Cancelling a false alert: If you accidentally send a false distress signal, you must cancel it immediately. Send a “Distress Acknowledgment” or “Distress Relay Cancellation” message on the DSC channel. Follow up with a voice announcement on the appropriate working channel to inform nearby vessels and shore stations that the distress alert was sent in error.

DSC Compatible Equipment and Integration

Radios with built-in DSC

Two main types of radios come with built-in DSC functionality:

  1. VHF: These are popular among recreational and small commercial boats due to their relatively short range and ease of use. As mentioned, Channel 70 is designated for DSC use in VHF communication.
  2. MF/HF: Larger ships operating in more remote areas use these radios, which have a greater range than VHF radios and are suitable for communication in more challenging environments.

DSC integration with other marine equipment

DSC can be integrated with various equipment to enhance safety and communication capabilities:

  1. GPS systems and receiver interconnect: Connecting your radio to your GPS ensures accurate location data is included in distress alerts and other DSC messages. This allows for faster and more precise responses in emergencies.
  2. Chartplotters: Integration with electronic chart systems allows you to visualise DSC calls on a digital map, providing a more intuitive way to manage communications and navigate complex situations.
  3. Automatic Identification System (AIS): When integrated with an AIS system, DSC can display nearby boats’ positions, speeds, and other information, enhancing situational awareness and helping to prevent collisions.
  4. Radiotelephone and antenna systems: These radios can be connected to existing radiotelephone and antenna systems, allowing you to use your communication infrastructure more efficiently. This can help reduce equipment clutter and simplify onboard communication systems.

Final Thoughts

DSC is a crucial communication system that plays a significant role in improving maritime safety and efficiency. You can take full advantage of this powerful communication tool by understanding its features and capabilities and how to use and integrate it with other equipment properly.

With DSC, you can streamline routine communication, enhance vessel coordination, and ensure a safer and more efficient marine environment.

FAQs

What is Digital Selective Calling (DSC)?

Digital Selective Calling is a communication system used primarily with VHF radios to enhance safety, efficiency, and coordination at sea. DSC allows for selective calling, group calling, and automated distress alerting.

What is the Global Maritime Distress and Safety System (GMDSS)?

The GMDSS is an international system designed to improve maritime safety by ensuring effective communication between vessels and shore stations. DSC plays a vital role in the GMDSS by sending distress alerts and providing selective calling features.

How do I program my DSC radio with my MMSI?

To programme your MMSI, access your radio’s menu system, look for an option related to MMSI or DSC setup, and enter your nine-digit number. Consult your radio’s manual for specific instructions.

What are the benefits of integrating DSC with other marine equipment?

DSC integration with GPS systems, chartplotters, and Automatic Identification Systems (AIS) enhances safety and communication capabilities. This allows for faster and more precise emergency responses, better situational awareness, and more efficient use of onboard communication systems.

Previous Post

Sail Trim: Speed, Stability, and Performance

Next Post

Boat Transom: A Comprehensive Guide

Related Posts

NMEA 2000 engines
Boat Tech

NMEA 2000 Network Explained

June 15, 2023
epirb vs plb
Boat Tech

EPIRB vs PLB: Which is Right for You?

May 27, 2023
what is chirp sonar
Boat Tech

What is Chirp Sonar?

July 6, 2023
Next Post
outboards on boat transom

Boat Transom: A Comprehensive Guide

Leave a Reply Cancel reply

Your email address will not be published. Required fields are marked *

Categories

  • Anchoring & Mooring
  • Boat Anatomy
  • Boat Culture
  • Boat Equipment
  • Boat Safety
  • Boat Tech
  • Boat Types
  • Navigation
  • Propulsion
  • Sailing Techniques
  • Contact
  • About us
  • Cookie Policy
  • Privacy Statement
  • Disclaimer

© 2023 TIGERLILY GROUP LTD, 27 Old Gloucester Street, London, WC1N 3AX, UK. Registered Company in England & Wales. Company No. 14743614

No Result
View All Result
  • Anchoring & Mooring
  • Boat Anatomy
  • Boat Culture
  • Boat Equipment
  • Boat Safety
  • Boat Tech
  • Boat Types
  • Navigation
  • Propulsion
  • Sailing Techniques

© 2023 TIGERLILY GROUP LTD, 27 Old Gloucester Street, London, WC1N 3AX, UK. Registered Company in England & Wales. Company No. 14743614

Welcome Back!

Login to your account below

Forgotten Password?

Retrieve your password

Please enter your username or email address to reset your password.

Log In

Add New Playlist

Manage Cookie Consent
To provide the best experiences, we use technologies like cookies to store and/or access device information. Consenting to these technologies will allow us to process data such as browsing behavior or unique IDs on this site. Not consenting or withdrawing consent, may adversely affect certain features and functions.
Functional Always active
The technical storage or access is strictly necessary for the legitimate purpose of enabling the use of a specific service explicitly requested by the subscriber or user, or for the sole purpose of carrying out the transmission of a communication over an electronic communications network.
Preferences
The technical storage or access is necessary for the legitimate purpose of storing preferences that are not requested by the subscriber or user.
Statistics
The technical storage or access that is used exclusively for statistical purposes. The technical storage or access that is used exclusively for anonymous statistical purposes. Without a subpoena, voluntary compliance on the part of your Internet Service Provider, or additional records from a third party, information stored or retrieved for this purpose alone cannot usually be used to identify you.
Marketing
The technical storage or access is required to create user profiles to send advertising, or to track the user on a website or across several websites for similar marketing purposes.
Manage options Manage services Manage {vendor_count} vendors Read more about these purposes
View preferences
{title} {title} {title}
Manage Cookie Consent
To provide the best experiences, we use technologies like cookies to store and/or access device information. Consenting to these technologies will allow us to process data such as browsing behavior or unique IDs on this site. Not consenting or withdrawing consent, may adversely affect certain features and functions.
Functional Always active
The technical storage or access is strictly necessary for the legitimate purpose of enabling the use of a specific service explicitly requested by the subscriber or user, or for the sole purpose of carrying out the transmission of a communication over an electronic communications network.
Preferences
The technical storage or access is necessary for the legitimate purpose of storing preferences that are not requested by the subscriber or user.
Statistics
The technical storage or access that is used exclusively for statistical purposes. The technical storage or access that is used exclusively for anonymous statistical purposes. Without a subpoena, voluntary compliance on the part of your Internet Service Provider, or additional records from a third party, information stored or retrieved for this purpose alone cannot usually be used to identify you.
Marketing
The technical storage or access is required to create user profiles to send advertising, or to track the user on a website or across several websites for similar marketing purposes.
Manage options Manage services Manage {vendor_count} vendors Read more about these purposes
View preferences
{title} {title} {title}