here is how the hulls would come over from China.
They are the FAT CAT 39' x 7' 11" and 7" deep and 1/4" steel.
The lids are 3/4" wider and 1/2" longer than the hulls, for idiot proof easy welding at the launch site.
Not show are any bulkhead or stringer options.
Hulls shown here are the cheap ones for Houseboats or Platforms, hence only a "draft" to allow the bottoms of the hulls to be stacked for shipping/trucking, and made entirely of flat 1/4" steel plate(coated with epoxy or whatever).
Unlike standard pontoons or modular floats, these have plenty of "basement space" for personal storage(houseboat) or HVAC/plumbing/septic, or even a bunch of modular flotation thingys for extra back up flotation if the hull gets holed.