Pete and Floppy Frog,
The beams on the Trailex trailers are 8.5 feet wide, which, if I am not mistaken, is the maximum legal trailer width in the U.S. Therefore, there is plenty of adjustment room for cradles for boats that up to 8.5 feet wide. That particular trailer used to carry a Nacra 6.0.

The flatbed that we put on that trailer goes exactly to the ends of the beams, and the boats are within that. Waves are a lot narrower than bigger cats, so it was possible to nest them upside down and rightside up. I know the load looks wider, but it is not.

Here is what the trailer looks like without boats on it. It is just two sheets of 4'x8' plywood, with a little space in the middle to bring it out to the 8'6" width.