I was thinking I could make an arched deck--but it's easy to put an arch that runs cross-wise; not so easy to put one in that runs lengthwise, though I could set up a form for the deck--but then the deck might have to be fairly large...

And it's not unusual for me to put a canoe on the rack by resting the tip of the upside down canoe on the rack and walking it forward. A flat deck doesn't get in the way of this maneuver; an arched deck probably would.

Though a Wee Lassie II might be light enough that I didn't need to do this.