If it is under a foreign flag, why would it need to comply with a US law? You see how repealing the Jones Act would open up a whole new can of worms. As far as I know, there is no precedent to this scenario unless you go back to the pre-Jones Act days, which would be history and probably not relevant to today's situation. Don't foreign ships calling at US ports abide by SOLAS and not the US Safety at Sea Act. But if a foreign vessel is engaged in domestic operation, as opposed to international, what then? Are the cruise vessels operating on rivers in Europe, not going to sea, but maybe going through different countries, abiding by the laws of the country they are in, or the laws of their flag of registry, or SOLAS?