Brian Duthie <firstname.lastname@example.org> asked the U.S. FCC Wireless Telecommunications Bureau about using U.S. radios in Canada. This U.S. government department has a Fact Sheet about boaters required to have a station licence to operate in Canada even though not required at home. (You require a Radio Operator's Licence (ROC) to transmit on a VHF radio in Canada.)
Their reply in June 1999:
Date: Fri, 18 Jun 1999 12:55:17 -0400
Subject: Re: Ship Station License (Form 506) needed to operate in Canada?
Title 47 Rule Part 80 requires a ship station license for international voyages. These rules are consistent with the legal authority the Commission has under the Communications Act. The 1996 Telecommunication Act allowed the Commission to license some vessels by rule on domestic voyages. Section 307(e). Licensing by rule eliminates the need for individual licenses for VHF radios and EPIRB on board certain ships operating domestically within the U.S. Canada has recently made similar changes to their domestic rules.
U.S. flag ships in international voyages are bound by any bi-lateral agreements we have with Canada and any multilateral agreements or conventions that the U.S. and Canada are a party to. So far, these rules have not been changed. Therefore, any U.S. registered vessel traveling to Canada would require licensing through the FCC.
Thank you for your inquiry.