Yeah, we double tow (often mistakenly called triple towing), with a cargo trailer behind the 5th wheel. It takes a bit more maneuvering unless you find pull through RV sites. :wink:
About 13.5 feet is going to be the max height in most states. And can you imagine the instability of the weight of a C-Dory above a car?? :shock: Or, the engineering involved in creating a trailer that could really handle the load?
For years, we towed a sailboat that was 38' long on the trailer behind a 40' motorcoach. It had a 10,000 pound towing capacity, but most states have towing limits (65' to 75', depending on the state) without a CDL with an endorsement. Having said that, Joan drove separate with an SUV that was our daily driver and launch vehicle. Some ramps can be too tight for the turning radius of a motorhome.
We finally came to the conclusion that we can't take it all with us, all the time... without a lot of hassle. So, we take turns boating and RVing. Oh, a small boat (like a Porta-bote) can be easily carried, and we did that for several years, too. But, it wasn't as satisfying as a "real" boat. :wink: But, sometimes you just want to get out on the water.
I've seen custom trailers (check out some of the Featherlight offerings) where they will engineer whatever you want. You may have to go with a toter-home instead of the Alpha to handle the towing weight. One trailer we saw was two levels high with a Jeep Grand Cherokee on a lift inside and Harleys underneath. When I saw that, I didn't think "wretched excess", I thought "I need to make more money." Someone pick Bill up off the floor. 8)
Of course, the easy way to take a motorhome and a cabin boat like the C-Dory is to simply drive separate. Tow the boat behind one or the other. We used handheld radios when we did that... and, while it works, it isn't as much fun as riding together. Joan finally said that she didn't want to drive separate anymore, and I agreed.
House... RV... boat... plenty of decisions. I am to the point that one of those is getting less important. Anyone wanna buy a cute little house on the water with a dock right out the back door? Then, we just need a good place to store the RV when we're on the boat and vice versa. Yeah, I just know someone is going to jump in here and say something about the boat BEING the RV. Ask that Alpha owner (the coach in the photo that started this thread) if a C-Dory is as luxurious as his coach. Oh sure, the coach doesn't float. You say po-tay-to, I say po-tah-to; you say boaterhome, I say not the same... but both can be great.
8)
Might be easier to get a REALLY BIG boat with a deck large enough to haul your RV... all it takes is money... lots of money.
Best wishes,
Jim