I'll be interested in seeing the different ideas on this as well. There was a recent thread on here about a very slick beach cart/highway trailer combo where the sib sat on a beach cart which in turn sat on a highway trailer. I'm wanting to design a collapsible cart that can be folded into a compact enough package that it can be easily transported on the boat then be used for portages. I currently have a pair of these tires
http://www.casterland.com/webstore/p...d=3119&sub=255 mounted on some very sturdy plastic rims that will be used for this.
I'm sure that if you had a set of floatation tires of this size or wider on your ATV trailer, it would not likely bog down in sandy bottoms.
Also 'Rogan' has a nice beach cart setup that uses 3 pairs of flotation tires. I'll see if I have an image of it in my picture bank.