Mike, there are currently 2 enclosed trailers in the CRAW group-
BOTH of which carry their F-18's, etc.- FLAT, horizontal in an enclosed trailer. One lives in N. Illinois. They may not be totally legal- but they've been getting away with it for years. Both of them were in Corpus in October 2014.

These trailers carry 2 boats flat, and a third disassembled under the bottom boat in the trailer also.