Yanni is recommending this cart:
http://www.kayakfishingsupplies.com/...ch-Cart/Detail
And for good reason. They are worth the extra cash if your wheeling across the sand.
Just think of it the same way as you do the people that get stuck at the Launch. Notice that trucks (even 2wd) with lets say 33x12.50 Tires get stuck far less often than cars with tires that are 2-3"+ smaller across and much smaller in diameter. More surface area means less sinking into the sand and requires less effort or move through it. A larger Diameter means that you have less chance of the whole tire getting into a hole and digging in as well. And by airing down you create more surface area and traction so that you do not dig in. The ballon tires on these cats work very well at a super low PSI