But why do cruise ships have to call on foreign ports? The reasoning is a bit convoluted, but it's tied to the Merchant Marine Act of 1920, which, in part, regulates the transportation of goods (Jones Act) and people (Passenger Vessel Services Act of 1886) on ships that aren't registered in the United States.

This is primarily due to the Passenger Vessel Services Act of 1886 (PVSA), a U.S. law that prohibits foreign-flagged ships from transporting passengers directly between two U.S. ports without visiting a "distant foreign port." Since almost every major cruise ship—from lines like Carnival, Royal Caribbean, and Norwegian—is flagged in countries like the Bahamas or Panama, they must include a foreign stop to avoid massive fines (currently around $941 per passenger in 2026). For cruises traveling between Seattle and Alaska, Canada is the closest and most logical foreign destination, making stops in Vancouver or Victoria a legal necessity. Without this stop, the cruise would be considered a "domestic voyage" reserved exclusively for U.S.-built, U.S.-owned, and U.S.-crewed ships, a category that currently only includes the Pride of America in Hawaii.