This is my canoe on wheels. These are sold by several folks on eBay and Amazon and can be had for $35 including shipping
to the lower 48.
I really found them handy for getting up and down the ramp
with a 140 lb canoe (with outboard
and gear). If you run into a rock or a pothole, your boat
will slide. Just tie your dinghy
, canoe, kayak
to them and be careful. They fold flat and the wheels are easily removable. It takes up little space. I didn't try them in sand yet but will next year.