That's a sweet little canoe. I might mount a shotgun holder up front - http://crowwingkayaks.com/index.cfm/pageid/39
or build something to hold the shotgun off the bottom of the canoe inside on the side. I know I get water inside of the canoe all of the time. I keep $1 dollar spring clamps front and back on my canoe from Home Depot - they are fast tie downs to brush or sticks (usually where I am fishing). I use 7mm cord and attach to the canoe with a prusik (fast length adjustment). There are already holes in the clamps which just happen to be about 7mm.