[Airslot]

Here's another thought. Make your cut about 6" from the gunnel all the way around. If using 3/4" ply, build up the stringers by laying a piece of your 3/4 right on top of them. When you lay the new floor, lay it across the built up stringer and run it to about 2" from the gunnell, on top of the factory floor. Round over the outside edge of your new floor and you have a nice "drain channel all the way around your deck. My neighbor is a glass guy and he does most all his rebuilds this way. He also uses liquid nails to glue it down and uses drywall screws (glued and screwed) before he glasses over it.

Airslot