In the photo of the vernable Derald Stewart boat above you can see the opening in the deck for the two front passengers is complete. It goes all the way from side to side and all the way down to the bottom of the boat. The front passengers sit there as if on a kitchen chair with their knees bent 90 degrees, with feet straight down. All the way to the floor.
So when you temporarily swamp a boat in big water that front seat well fills up with a huge amount of water and it takes a while for it to drain, electric sump pumps not with standing--which makes any boat unmanageable for a few moments, while it drains.
Here is a public domain stock photo of a person sitting on a car seat. The legs go almost straight out. You can sit that way all day long and it brings the floor up a good 12" inches or so. So here's my point. If the front seat well on a decked boat was modeled after a car seat so the floor was not so deep it would fill with less water. You could reduce that amount too by not extending the opening all the way left and right. Make two side by side wells just big enough to sit in.
If you are building a wide boat, say 66" inches wide instead of 48" or 54" inches, then you could raise those seats up a few inches too, without losing stability. At that point you'd hardly be shipping any water all.
Yes. My idea is to build a decked white water boat that is extra wide, that is a little like a sit on top kayak. There will be seat wells for the rower and passengers. But they won't be all that deep. Any stability lost by pushing the payload a little higher will be more than offset by the extra width. 66" inches is a full foot wider than 54" inches. The original Briggs is only 48" inches wide.
My 56" Inch Honky Dory is so much more side to side stable than a Briggs it's hard to put into words. You have to row both to really know how big that difference is. A 66" inch boat will be like an aircraft carrier. I'm assuming it will still handle well too, because of its rocker profile. That much remains to be seen. The proof is always in the rowing. You never really know 'til you row.