[Blue_Heron]

I think the thru-hulls are going to vary from year to year and mfgr to mfgr. I have an '83 20sf made by Seacraft Industries and it has the two in the transom for bilge and livewell, but the livewell plug is to port of centerline. I also have a factory clamshell/seacock about a foot forward of the transom and an in-hull transducer (long abandoned). While some of the Potter Hull cockpit drains exit through the bottom of the hull, mine exit through the transom just above the trim tabs. I also have a thru-hull drain at the forward fish box, two bilge pump outlets, one port, one starboard, and a live well pump outlet to port.
Dave