Amateur radio and HF
marine radio are two entirely different things.
Your amateur radio operator
license and call sign is not valid for the marine HF bands.
For that you need two things:
1. A station
license for the vessel. In most countries dead simple to get. This gives you the call sign, which for marine HF is associated with the vessel, not the operator.
2. An operator license for you. In the U.K., it's a Long Range Certificate. In the U.S., it's the same no test FCC license you use for
VHF. In Canada I have no idea, but
Google is your friend.
Now that being said, most sailors with
HF radio operate on the amateur HF bands as well as marine SSB bands. On the amateur bands, you don't use the vessel call sign, you use your amateur radio call sign, and you need a valid amateur radio license. Whether your UK license is valid in Canada, I have no idea. U.K. is in CEPT, so probably it is, if it's in date, and if there is no requirement to get a Canadian license due to your residency. Again,
Google is your friend. I have an U.S. Extra Class license which is reciprocally valid in CEPT countries (the U.S. is not in CEPT), but there are certain conditions. On my
boat, which is UK flagged, I operate "/MM" -- maritime mobile.