[Mark]

The in-floor fishbox in front of the splashwell could be plumbed with a macerator & aerator and used as a livewell. That would also prevent having to bail it dry while on hands and knees at the end of the day. It would also keep the center of gravity considerably lower.

An extra 40 gallons of water (250#'s) in the tail end of an SC18' is not a dream scenario. Would a small Kodiak under a standard leaning post work out, or do you really NEED 40 gallons?

If you still have the 20" transom and you DO put in a large livewell, you should probably also add some sort of additional splashwell gate much like the ones in the 23's. With another couple of hundred pounds in the boat, you WILL take waves in over the transom right onto the deck while sitting still in average conditions. A 25" transom will negate some of this but not entirely.

Just the thoughts of an ex-18' owner/
mark