What does Placid Boats have to say about this?  MP did they have any suggestions for you about portaging? 

I'll answer this.  From their site:

What's the best way to portage?    

Our boats come with two portage pads.  They store on the thwarts and are placed on the rails for portaging.  The boats are typically carried on one shoulder; the second pad protects your hip from the boat bouncing against it as you walk.  We also offer a fabric portage yoke which allows comfortable overhead portaging.