Thank you all for your replies.
Greg S, since posting I have heard back from TC and you come closest to the prize.
This question came about when a friend had his boat on the hard in Nanaimo and while there, found a good deal on a new VHF. He was told by the merchant, an endorsement to the ROC-M was required. He then checked with a local, former CPS instructor who advised it wasn’t legal for the store to sell a VHF with DSC to a person with no DSC endorsement.
The more the questions, the more confusing the answers, so your comment about not having a definitive answer is on the mark and is why I contacted TC.
In typical bureaucratic fashion, after being passed to three subsequent contacts, I received the official response from TC, or more specifically, Spectrum Management Operations Branch / Innovation, Science and Economic Development Canada / Government of Canada:
>>To operate a VHF or Single Side Band radio in Canada, you must have an ROC-M certificate. The ROC-M certificate with DSC Endorsement certifies you to operate VHF and MF/HF (single side band) radios in Canada. Basically, it is not required but if you got your ROC-M license before the DSC component was added to the course you are encouraged to get the DSC endorsement if your radio is equipped with DSC.
For a vessel carrying 12 or more passengers DSC is required and the DSC endorsement addition to your ROC-M license is required as well.
There is more information in the below link.
Bulletin No.: 04/2002 (canada.ca)<<
The question of cost arose because the only way for a holder of current ROC-M to get the DSC endorsement is to challenge the exam at a minimum cost of +/-$100, or take the entire new ROC-M course at +/-$250, depending on where the course is taken.
To further muddy the waters, CPS is the ROC-M administrator and license issuer.
Like you, Jim and SteveK, I am a long time holder of the ROC-M (1983) and don’t want a new issue if not needed.
The linked information is yet another example of bureaucracy gone mad, as it is contradictory and lends itself to an individual’s interpretation. As well, it is very common these days, especially with social media, for everyone to be an expert. That former CPS instructor mentioned above also stated, ROC-M courses could not be taken without a CDN (Candidate Document Number). CDN for this purpose was discontinued in 2016.