How will DSC affect you?

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ffemtbland

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While online this evening, I came across what seemed to look like a reputable website ... Has the USCG stopped listening to 156.8 MHz FM? I hope not ... I've only got a handheld - no DSC capabilities ... What about 2182 kHz SSB? My guess would be that it's taking a little longer than expected to get DSC fully implemented ...

FROM WWW.YBW.COM

"How DSC will affect you?"
"From 1 February 1999 SOLAS vessels are no longer required to monitor the 2182kHz MF distress frequency.
From 1 February 2005 they will no longer need to monitor the Ch16 VHF distress channel. On the same date, Coastguard rescue centres will cease to keep a dedicated headset watch on Ch16, and rescue centres in other countries may stop listening on the channel altogether."

Lars Bland
KC9JMD
Madison, WI
 

OceanaRadio

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ffemtbland said:
While online this evening, I came across what seemed to look like a reputable website ... Has the USCG stopped listening to 156.8 MHz FM? I hope not ... I've only got a handheld - no DSC capabilities ... What about 2182 kHz SSB? My guess would be that it's taking a little longer than expected to get DSC fully implemented ...

FROM WWW.YBW.COM

"How DSC will affect you?"
"From 1 February 1999 SOLAS vessels are no longer required to monitor the 2182kHz MF distress frequency.
From 1 February 2005 they will no longer need to monitor the Ch16 VHF distress channel. On the same date, Coastguard rescue centres will cease to keep a dedicated headset watch on Ch16, and rescue centres in other countries may stop listening on the channel altogether."

Lars Bland
KC9JMD
Madison, WI

Lars,

That yachting magazine story was out to lunch. Ch-16 remains the International Calling and Distress channel for VHF-Marine. What DSC will do when boaters get around to learning how to use it, is allow the rules to change to prevent any general calling on Ch-16 and reserve it for distress only. That may happen in EU states much sooner than the US. In the Great Lakes and all US waters a boater who is voluntarily equipped with VHF-marine radio must be listening to Ch-16 if underway and not using the radio to communicate.

That hardly enforceable requirement will soften when Rescue-21 installation is complete in all US-areas. That is because a DSC-capable radio has a separate receiver that always listens to CHF Channel 70 for DSC calling or distress, when the radio is turned on. And as you will see below, monitoring Ch-16 will become less inportant when all radios are DSC capable (but they still need to be turned on!)

When a DSC Distress call is received on a DSC radio, the following things happen:

1. All radios that receive the call emit a very loud alarm for at least 1 minute.

2. The Maritime Mobile Service Identifier (MMSI) of the distressed vessel is logged in a screen-display and firmware memory of all receiving units.

3. The position of the distressed vessel (if they properly connected a GPS to their radio) is also logged and displayed on the same screens and memory,

4. The nature of distress (if one was selected when the distress call was made) is also logged and displayed.

5. All radios that received the DSC distress call are then electrically commanded to Ch-16, where all persons who heard the DSC are expected to listen for follow-on voice of the distressed vessel, who should be repeatting his MAYDAY details in voice.

6. A shore station (USCG here) are the only units allowed to acknowledge a DSC distress call. If after a resonable period of time (generally 3-5 minutes) there is no acknowledgement of the distress by a shore station, then a vessel who heard the DSC distress message should RELAY the distress call via DSC. Presumably a shore station that missed the original distress call could hear and acknowledge another vessel's relay.

DSC distress calls automatically repeat over and over until they are acknowledged or stopped by the operator by turning off the radio, or by cancelling the distrsss via DSC message.

The completion date for the USCG Rescue 21 system which installs DSC systems in all USCG Sectors and Sector Field Offices has now been moved back to 2011. It is however already installed and operational in several East Coast, Gulf Coast, and West Coast USCG Sectors. The Great Lakes will be the last to see the finished system.

USCG Sectors and Sector Field Offices will guard Ch-16, Ch-70 DSC and 2187.5 KHz DSC.

The USCG will probably always guard Ch-16 for the foreseeable future (20 years anyway).

All commercial and compuilsory-equipped vessels must maintain a listening watch on Ch-16 at all time swhen underway, except when inside Vessel Traffic System waters, in which case in the US they must then listen to Ch-13 (Bridge to Bridge Act requirement). Boaters in local waters seem forever ignorant of this rule, and make endless calls to container ships/tugs/tankers etc on Ch-16 when they should know better.

2182 KHz: Watchkeeping requirements for compiulsory equipped vessels to maintain listening watch on 2182 KHz are gone. They must however scan all 6 DSC-GMDSS frequencies when underway beyond Sea Area A-2 (coastal waters/20mi out to 100 miles). Inside A-2 they must listen to DSC-2mhz (2187.5 Khz).

The USCG continues to guard 2182 KHz from all USCG Sectors (except inland or inner Bay Sectors such as Sector Lower Mississippi or Sector Delaware Bay, for instance). This will also continue for the foreseable future.

Regards,

Jack Painter
District Communications Officer
Fifth Coast Guard District-Sr
United States Coast Guard Auxiliary
 
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ffemtbland

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Wow - Thank you so much for the information. It seems getting a straight answer on the topic has been difficult with only Google!
Lars
 
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