Even though the FCC says:
"WHAT IS DOMESTIC OPERATION?
Ships are considered as operating domestically when they do not travel to foreign ports or do not transmit radio communications to foreign stations. Sailing in international waters is permitted, so long as the previous conditions are met. If you travel to a foreign port (e.g., Canada, Mexico, Bahamas, British Virgin Islands) a license is required. Additionally, if you travel to a foreign port, you are required to have an operator permit as described in Section III. "
The US CG web site says:
"I live in the Detroit area. Does domestic use include Canada? If I land in Canada and use my VHF radio, do I need a license?
Technically, yes. Although the FCC no longer requires boaters having a VHF radio for domestic use to carry a ship station license, ship station radio license for my boat since the FCC eliminated its licensing requirements. U.S. boaters are supposed to obtain a license from the FCC before coming to Canada. We understand Canada, like the US, do not require boaters with VHF radios carry ship station licenses. (Note: Canadian rules regarding radio licenses on boats could change at any time. We recommend you check with Canadian authorities.)"
And from "Boat Maine"
"If you may enter foreign waters, including Canada, there is a compelling reason to get a FCC License. This is because when you apply for an FCC license you can get a MMSI number from the FCC at no additional cost. MMSI numbers issued by the FCC differ from those issued by BoatUS in that FCC assigned MMSI data is shared with search and rescue (SAR) agencies in foreign countries. This is important because if you push the distress button on the radio in foreign waters, the SAR station will take the number they receive and attempt to look it up in their MMSI database. If the number is from the FCC, they will have the information they need about your boat. If however the number is from BoatUS, they may be unable to find any data on your vessel. Needless to say, in an emergency you do not want to do anything to impede a speedy rescue."
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