Carl,
When I hunted with my Durham in my sneakbox, I always hunted with her laying down between my legs. She was to big to fit under the spray shield. I'd cover her up with a camo burlap with her head just resting on the back deck. If she popped up, her head was even with my outboard cowl cover so I had no shots either way. I shoot long barrels no less than 28" when I hunt ducks so I never felt she was feeling any muzzle blast.
On really nice days, she'd just sit on the bow behind the shield.
My new dawg, Chance, is bigger and I stress the "down" command when I train him. I'm hoping he'll do as well as Durham.
If I could fit either dog behind me, I'd choose that option first. That was one of the reasons why I liked and bought the Momarsh fatboy DP. (plus you can never have too many duck boats)