It depends on your size, boat size, depth of the V hull, how low you can mount the plywood. You could always try putting a piece in as low as possible into the hull, PUTTING YOUR LIFEJACKET ON, and taking it out about twenty feet offshore and cast for a while. In any case, even if you make it all work, you should have a lifejacket on if you're out there past where you can safely swim back to shore (while towing a swamped rowboat and possibly in very cold water).

Safety nag? Yup. But yeah, you could probably mount something down low into the V that you can stand on.

Take pictures and show us what you got.