I think the issue is that a non-Jones ship going from DR to PR could then not continue on to another US port, which means that PR would have to have enough demand to unload the entire ship there or at another foreign port.
The issue really comes into play with the fact that a non-Jones ship couldn't stop at a US port on the way to another US port, and that really hurts smaller outlying ports that are between a foreign nation and mainland US.
The issue really comes into play with the fact that a non-Jones ship couldn't stop at a US port on the way to another US port, and that really hurts smaller outlying ports that are between a foreign nation and mainland US.