Boating Equipment & Product Review/Test; VHF and DSC Digital Selective Calling

The new Digital selective calling (the red button DSC) that you see on modern day VHF radios is a technology that can add many features to your VHF radio. One of the features is

receiver of your VHF transmission will be able to read you current position and Lat & Lon.

This is achieved by connecting your DSC enabled VHF to a GPS and registering for a MMSI number. In an emergency someone receiving your distress call knows your location instead of having to search.

General discussion on VHF Communications

The most important reason to have a marine VHF radio onboard is safety.

VHF or Cellular Phone The Coast Guard does not advocate cellular phones as a substitute for the regular maritime radio distress and safety systems recognized by the Federal Communications Commission and the International Radio Regulations -- particularly VHF maritime radio. However, cellular phones can have a place on board as an added measure of safety. More

Marine radio VHF Information for Boaters Much of the information presented here is courtesy of the U.S. Coast Guard and the FCC. You have the option of selecting one of the questions below to go directly to that information or simply start with "Who needs a radio?" and scroll through the entire article. More

- Area A1 Within range of VHF coast stations with continuous DSC alerting available (about 20-30 miles)

- Area A2 Beyond area Al, but within range of MF coastal stations with continuous DSC alerting available (about l00 miles)

- Area A3 & Area A4 The remaining sea areas. More

What is Digital Selective Calling DSC

Don’t have DSC? It’s time to get it. Since the installation of the new Rescue 21 emergency communication system last December, DSC will not only save your life, it also will simplify it. Digital selective calling (DSC) works by transmitting a hailing signal on channel 70. The complete Mayday call, including the identity of your boat and its precise position, is sent in about one-third of a second. Once initiated, your call will be automatically repeated until the Coast Guard answers. If you wish, the signal can include the specific nature of your distress and the number of people on board. Because it’s digital, the message transmitted on channel 70 can get through to the Rescue 21 system when conditions make voice calls difficult. Once your Mayday call is received, it will be automatically recorded and will alert the crew on every boat with a VHF/DSC radio in range of your transmitter (up to 200 square miles). More

They tell you which CG stations are currently running Rescue 21 and the types of DSC receivers from Class A (All DSC options provided. Required on MF/HF and VHF radios used by SOLAS-regulated ships. Class A includes polling and vessel tracking, data, and numerous other functions in addition to voice) to Class E Minimum DSC capability for HF marine radios carried by recreational boaters, commercial fishing vessels, and other non-SOLAS regulated vessels. Class E required capabilities include: . More

VHF -DSC info Includes DSC information and MMSI number registration for Australia

Marine communications changed for ever on February 1, 1999, with the introduction of the Global Maritime Distress and Safety System or GMDSS. The GMDSS has automated many marine radio functions and processes, particularly those related to distress and safety. The GMDSS is an amalgam of a number of individual radio systems. Whilst satellite-based systems do play a part in the GMDSS, ‘normal’ terrestrial radio continues as the primary system for ship-ship and ship-shore communications. The GMDSS has automated marine radio distress alerting by the use of a technology known as Digital Selective Calling (DSC). More

Test your DSC
To test your DSC capability send a "test" transmission to a Coast Guard stations MMSI number.

As noted here a problem with DSC is false alarms, accidentally sending a distress signal. If this happens is no good just turning of the alarm, since the Coast Guard and other vessels have received your distress call. You must broadcast on CH 16 the false alarm. That way USCG and other boats equipped with DSC will know not to respond and send out SAR teams.

To enable the features of DSC you will have to register your VHF and get a MMSI number. MMSI stands for Mobile maritime service identity. These are places you can register for the MMSI number.

Boat US

Coast Guards Rescue 21

USCG Rescue 21
Coast Guard has implemented a recapitalization program entitled Rescue 21. When finished, Rescue 21 will replace a wide range of aging, obsolete radio communications equipment to include:

Rescue 21 revolutionizes how the Coast Guard uses command, control, and communications for all missions within the coastal zone. The system:

Full implementation of the system is not until 2011. The chart here shows which areas are completed and which are due.

VHF Manufacturers VHF DSC & GPS

These manufacturers and devices below are only an example of what technology can do. There are solutions from a host of different manufacturers, so check your favorite brand to see what DSC and position Reporting can do for you.

We are going to concentrate on other features of VHF DSC radios. To get the full features of DSC you must also connect your VHF DSC unit to your GPS unless you have a combination unit.

C-Map

Here is an interesting feature Using Digital Selective Calling (DSC). Any vhf chart plotter combination can display a VHF Distress Call or Position Request call when input is received from a DSC equipped radio capable of sharing the data. For example you can send your position to your friends chart plotter, he then hits GO To and he will get a bearing on his chart right to you. C-Map can be used with Furuno, Simrad, Navman, Si-tex, Standard Horizon.

New range of integrated VHF with GPS chartplotter hailer and fishfinder. This is the CPV350 and there are other sizes. This one instrument seems great for the small boat where you need VHF and charting ability. DSC able NOAA weather alert, AIS capable and optional fishfinder. Prices have been advertised in the $900 region.

The CPV 350 includes DSC polling, Position request, the capability to poll (request and send) the GPS location of another vessel. This is a great feature for anyone wanting to know the position of anther vessel for example your buddy that is catching fish, or finding the location of a person you are cruising with. See C-Map chart above. Standard Horizon uses C-Map cartridges.

The IC-M304 DSC capable Radio is an example of a radio that would connect to your current GPS via a NMEA 0813 cable. Prices as low as $150.

Position Request and Position Report

Over and above the DSC, your own and other ships’ position data can be exchanged with the position request or position report functions. The received position information can be transferred to external navigation equipment*. In addition, the polling (request/ reply) function checks whether a specific ship is within the communications range.

Uniden UM625C won the Freeman Pittman Award for is Class D DSC VHF. Similar features to the ICOM.

Raymarine Ray 54 VHF works with the Raymarine network supplying position reports to the chartplotter.

DSC capable handheld submersible VHF. This GPS full screen mapping VHF brings navigation plus communication into one convenient unit. You can navigate using COG and compass screens plus the ability to put in waypoints. Should you fall overboard and have this unit, you can send a position request to any DSC capable unit close by not just the one on the boat you fell off. You will be able to communicate your position with friends either cruisers or fishing if they have a DSC capable radio also. PC interface so you can download maps

Rino combination VHF/GPS. Navigate and

communicate on one device. It's waterproof and can "beam" your exact location to another Rino user on FRS Family Radio Service or General Mobile Radio Service (GMRS) Radio Range up to 5 miles using GMRS, up to 2 miles using FRS) (channels using "Position Reporting". Say you are fishing with friends you can see their position on your Rino and directions to them. $268 retail. This device does not have a distress button even though it has position reporting.

Rescue Services (non Emergency) Commercial

$144 year subscription. Not for distress but the operators can patch through phone calls help with marine problems.

Sea Smarts Automatic Vessel Location (AVL) capability lets land-locked loved ones track your boat's exact location right from your home computer. No more worrying the family if your fishing sojourns take you into the deep blue or off to the secluded hot spots where your cell has no coverage.

Sea Smart is currently available in the following coastal regions: Cuttyhunk, Mass. to Cape May, N.J. (including the entire Long Island Sound). East Coast of Florida from Jupiter Inlet to Marathon. West Coast of Florida from Cedar Key to Everglades City

Quick Response Nationwide
Hundreds of commercial tow boats committed to assisting NBOA members. NBOA is committed to dispatching the 1st available boat to assist you in an emergency. NBOA Dispatch is on duty 24/7/365 answering your calls for assistance. Call 1-800-234-2869 via your cell phone or the marine operator vhf radio and NBOA's dispatcher will do the rest. NBOA towing service is available anywhere in the continental USA. NBOA will dispatch a tower to assist you where ever you are.

VHF Instruction

If you want to learn more about using your VHF here are two books. The first is a guide that anyone can read. The second is a more advanced look and includes tutorials and interactive DVD.

Nearly six million U.S. and Canadian recreational sail- and powerboats carry VHF radios. Endorsed by the U.S. Coast Guard and written by a navigation VHF-DSC radio trainer, this user friendly guide gets boaters quickly up to speed on both analog and digital VHF radiotelephone usage. Its straightforward, non technical coverage, "Geek-speak" boxed definitions, quick reference chart, and more make it easy for readers to quickly master and get the most out of their radios.

VHF DSC Tutor is for professionals looking to get their radio license. Endorsed by the RYA

More and more vessels are being equipped with the new style of radio which has DSC (Digital Selective Calling). Only those people who have qualified for the new Short Range Certificate are now licensed to control the use of the this equipment. The SRC course is intensive, seeking to teach or revise all the basics of Marine VHF then cover all the new equipment and procedures, usually taking just one day.
This new Tutorial has been specially produced to make it much easier to get the best from the SRC course by covering the basics of VHF and VHF procedures, then introducing DSC and how it integrates with established methods. Typical DSC equipment is then examined and all the button-pushing procedures are animated. Users who then take the SRC course can concentrate on learning good communication skills, not just button-pushing.

$34 for the tutorial to $168 which includes the tutorial and the simulator with shared use on PC.

The Coast Guard responded, "Vessel Nique, this is Coast Guard Station Lake Worth, please state your position and the nature of your emergency."

I was in a high speed Sea Tow towboat on the west side of Peanut Island, less than a half a mile from the inlet. As soon as I heard the initial call, I headed out, violating (don't tell anyone) the slow speed zone. More

March 28th, 2007 - VHF communications

Communications News

General discussion on VHF Communications

What is Digital Selective Calling DSC

Coast Guards Rescue 21

VHF Manufacturers VHF DSC & GPS

Position Request and Position Report

Rescue Services (non Emergency) Commercial

VHF Instruction