In the summer of 1974 I worked as a water taxi operator in Howe Sound with the headquarters in Horseshoe Bay. One of the requirements of employment required me to get what I remember as being a Restricted Radio License for operating the radio communication equipment between the vessels and HQ. My understanding at the time was that the license was valid for life. I have lost my records of this license and wish to inquire where and through what avenue, so I may secure a copy... and even if the license is still valid in 2018.
According to this Canadian government web site, marine radio licenses are no longer required for vessels operating in Canadian waters only, and not the territorial waters of another country. If you're planning to travel to another country, then the thing to do is probably to contact Industry Canada to see if your license is still valid. (Here's a link to their "contact us" page.)
I suspect that you're referring to the Canadian "Restricted Radio Operator's" licence. This is a certificate of proficiency for operators of licenced aeronautical radios and in the past there were versions for maritime and commercial radio operators. I suspect that you probably had the now-obsolete maritime version for your job as a water taxi operator. The RRO licence doesn't grant any frequency privileges (it's not an Amateur Radio licence), any radio you choose to operate would still be subject to licencing for whatever radio service it's classified in so I can't see the RRO licence being of any use to you now. According to the current information for the RRO licence: "Contact your local district office of Industry Canada if your certificate is lost or requires replacement". The current RRO licence information is available at: https://www.ic.gc.ca/eic/site/smt-gst.nsf/eng/sf01397.html