Hey Seafarer - Thanks for the invitation to join you. I may take you up on it at some point in the future. Unfortunately, I am struggling to find time to visit our cabin, so it might be awhile. Your trip to the Gulf Stream sounds very interesting. Though I have chartered a big cat in the Abacos, I have only flown over the Gulf Stream. What little I know about it, it sounds very challenging for a kayak.
As you requested, I am attaching a photo of the Thule crossbar reinforcement. It is a 2" plastic drain pipe I got at Home Depot. I chose it over the white PVC because of color and the fact that it seems more rigid than PVC. I cut it long enough as to ensure constant pressure to hold the pipe in place, using a quicktie on the top in case of a trailer bounce. Because I have a carpet floor on the trailer, I didn't need to secure it to the floor. I hope this helps.
PS I also noted the cargo net. It works great for keeping life jackets, etc. from bouncing or blowing out of the trailer.