Since Transport Canada's announcement that they would ban cruise ships with a capacity over 100 for one more year, the industry has been scrambling to find a way to salvage a 2021 Great Lakes cruising season. Some approaches advocate sailing with less than 100 on-board, but with the number counting both guests and crew, this may not be economically viable for carriers.
Louis E. Sola, a commissioner at the Federal Maritime Commission has made a public statement endorsing a temporary suspension of the Jones Act. This is the Passenger Vessel Services Act (PVSA) which requires a stop in non-USA ports for foreign-flagged vessels. Sola says, "I encourage both the Biden administration and Congress to quickly review this issue and consider a limited exception to the PVSA while simultaneously engaging the Canadian government on the diplomatic front to address this particular problem."
The Transport Canada order, combined with the Jones Act effectively shuts down cruising for 2021. But with an exception to the PVSA, passenger vessels could operate a U.S.-only cruise itinerary with a full complement on-board.
Source: Federal Maritime Commission