I bought the Primex cart for my triple and it's a great way to go for a big kayak (my wife would have divorced me by now if she had to carry one end of a loaded triple every time we went). The inflatable wheels really glide easily over the rough stuff. The wheels come off and the cart folds down ok, but I suspect it would be hard to pack away in a single.

http://www.rei.com/cgi-bin/ncommerce3/CategoryDisplay?cgmenbr=8000&cgrfnbr=4501462&seq=1&sort=1

Can you maybe just get bigger wheels for your existing cart?

: I have a little cart that fits into the hatch. I find, however, that it's
: small and narrow wheels don't do so well over soft sand. I want to find
: out what my options are but a web search didn't turn up much. Any good
: plans available...or commercially made ones. I know they exist...I've seen
: them.

: Thanks, Dave Walker