Hi Robin,
When I drained the water out of Plebe Year, the small drain holes continued to weep for several weeks.
When I got the extra resin layer out of the Bilge well it had absorbed water and was still damp.
My thinking is that barrier coatings on the outside of the hull keep water out, but also keep water in.
So if water collects in the bilge well or keel void it will be absorbed by the hull fiberglass unless it is drained out.
Having drain holes that can be left open when the boat is on the trailer in the winter allows the water to drain out and the hull inside to dry out.
I may have addressed this problem with the large brass drain hole in Questar and Plebe year.
Questar is long term (20 years) Plebe year yet to be launched!
Jonathan Gorbold
Questar 1226