The 10th amendment constrains federal powers to enumerated powers when acting within the states. This act passed because in the seas the federal government was

The 10th amendment constrains federal powers to enumerated powers when acting within the states. This act passed because in the seas the federal government was not so constrained (yes hospitals and offices are on land but the loophole is they are only requiring them once you go out to sea). Congress in 1798 would have never went along with such actions on the inland populace, except perhaps in the territories.