Hi Oldfielder;
That’s a great question and why some guys are now raising the decks on the 23’ like the guys on the 20’ have been doing.
My water line on the outside of the boat is approx. where the 90 degree angle on the trim tab hinge plate is when I have a full tank of gas and 2 guys in the boat. I have one 225 outboard 2 stroke on the back.
On the inside of the boat when I had the through the bottom of the hull original scuppers you could see the water approx 1’ down from the top of the tube inside the deck. Those scupper tubes were in the middle of the square pocket in the corners of the deck.
If two guys were standing close to the scupper in the bay you still were OK But if you were drift fishing and two or three guys were standing close to the scupper trying to gaff a fish in 1-3’ or bigger seas water would come in and get peoples feet wet. If sea conditions were bad and I had 3 guys in the boat drift fishing we would have to fish one guy in the bow of the boat just to keep in from taking on some water or I would pull out the sea anchor/drift bag to have the bow of the boat to the seas.
That’s why I did the Vortex thread those things really worked well but they were not built to last long and restricted the flow of water out of the boat.
Saying all that when I drift fish and guys are in the back the water line will be some times way under the “at rest point” and sometimes way above that “at rest point”. No water back flushes these new scuppers.
Saying all that If I were to build another 23’ SeaCraft and I were going to put 2 motors on a bracket I would raise the deck during the re built so I could raise those Perko scuppers 2”, 3” or possibly 4” higher depending on how high I raised my deck.
FellowShip
Just for the Grins