I used to know but memory is getting shorter as life gets longer, but I think that 6 packs, uninspected, do not have to be built in the US. The Jones Act is what you will be dealing with and if it is required to be built in the US and you have a foreign built boat it literally takes an act of congress to get a waiver. Not impossible to do but difficult.
If you are one there is no explanation necessary.
If you arenít one, there is no explanation possible.