QUOTE:
"Recreational doubles are not allowed in some states and I do know that here in Michigan you must have a Recreational doubles endorsement on your license."
Only have to have an "R" (Recreational Double Endorsement) on your drivers license if your drivers license is issued in Michigan aa that is your state of residency. All it takes to get the endorsement is read the DMV little pamphlet and take the very easy commonsense test and pass it and you get the endorsement. Cost is a couple bucks.
If you live in any other state and have valid drivers license, you may double tow in Michigan without the Michigan endorsement.
Wife and I have had ours since 1992 and you do not have to retake the test when renewing your drivers license as they ask you if you want to keep the endorsement and you only need to reply "yes".
Our double tow rig (Crew Cab long box truck, 29' 5th wheel, 16-1/2' boat) measures 64' 11" as I had to cut 14" off the boat trailer tongue to keep it under 65'. Last time we actually double towed was in the summer of 2015.
Only stopped once in all those years and was measured and that was on Long Key in the Florida Keys by a Monroe County Sheriff in 1996. "He said we look awfully long" and then he took the wheel out of his patrol car trunk and rolled our length and then asked me if I knew how long we were? I said, 64' 11", and he said "have a nice day" and left! Double tow was totally legal in Florida in 1996. That same rig was towed thru 13 states without ant issues ever. Never personally heard of anyone else actually being stopped and measured with a double tow RV rig.
Yes, we have towed illegal at 72 feet long about half a dozen times in Michigan all the way to the Upper Peninsula when we towed our 3 axle 36' Carriage 5th wheel on the same size truck with the same boat behind but never was stopped or measured. 7' over the max legal length. We do see a lot of over length RV rigs on the roads and don't see them being stopped.