The Instep canoe cart is one of the best portage devices available. It has large bicycle type wheels, padded multi position bunks, a kickstand for load and unload and folds into a tight package for stowing.
Once centered, my boat rides along at slightly below waist level. It's like taking the canoe out for a walk.
The only disadvantage is the weight. At 17 lbs there are lighter portage carts available. But none are so easy to use and so well made.
I have also seen similar designs that were called the "Canadian Canoe Walker".