Thanks so much JS, This Hobie forum is a great place to learn and share and that's why I throw my friends designs out as food for thought.
The cart is still a work in progress. A winch was added recently, presenting some challenges, but the basic idea is sound, (join together 2 wheeleez beach carts anyway you can and add some padded rails).
I'm a fan of simplicity myself, and modular flexibility (as in 2 traxx carts). Batman's goal though, is to be able to safely transport, beach launch and recovery a TI sized boat solo.
If he adds those solar panels, motors and too much more, we may have to design a trailer for the cart though!
Please share what you come up with.