Love the Tsunami/ Hate the scuppers.

[abl1111]

The scuba valve idea would still be mounted toward the bottom of the scupper.

I envision it used with a pc of nice, wide pc. of 1.25" PVC tube epoxied into the floor ( obviously the present scupper would be history... )

The problem with any of these ideas is fouling. Thru transoms w/ Rabuds would work great too - if you dry stored your boat or cleaned them incessantly.

The Scuba Scupper needs someone to think about it...