Amazing. This whole long thread and the original question never got
answered, or, if it did, I missed it.

Let me rephrase and see if I can get an answer I was wondering about.

I have the licences because I plan to take my VHF to Canada and yack on it
there. I therefore have a call sign other than my boat registration
number.

Question: Should I use the radio call sign instead of the boat
registration?

I suspect, and what I will do unless someone tells me different, is use the
boat registration in US waters because this is what is expected and is most
in line with the licensing regime. Once in Canadian waters where the
applicabile regulations require the ship station and operators' licences,
thus the call sign, I will switch over to using the callsign.

Question: Does this make sense?

--
Roger Long