The exception for San Juan is sort of an enigma, as it is excepted from part of the PVSA rule, prohibiting cruises starting from one US port and ending in another (itself), but it is not considered a "distant foreign port" to serve as an intermediate stop, on say, a Fort Lauderdale to San Diego, Panama Canal cruise. Whether it would be considered "a near foreign port" for a cruise that would say go from say Fort Lauderdale to San Juan and return, without any additional foreign ports, I am not sure..Probably a moot point since.I don't think there would be any cruises that would ever sail that far with only that that on a round trip itinerary, anyway...🤷♂️