Retro tunnel hull?

[ted655]

Is there a practicle way to create a tunnel hull on this boat, without extensive cutting or modifying? Based on a "idea" a friend suggests as easy to do. He wants to add 2 appropriate shaped pontoons to either side of the bottom.
The hull is flat, 4' w X 18' l, (netted surface). It is aluminum plate, with a floor.
The intended purpose would be shallow river operations AND, retaining the outboard, not changing the lower unit over to jet drive.
So, is it as simple as welding 2 pontoon shapes onto the bottom?