Through Hull Drainage
 

I have a 1975 23' SF inboard that has a self bailing cockpit that drains through the hull. It is still out of the water, as we are re-powering it, and is being put in the water in a few days. I was just wondering if these drains work very well and how. I know they will work when the boat is underway, but what about when my boat is sitting on the mooring in a rainstorm? Will the thru-hull draining still drain the cockpit or will my boat simply collect all the water and fill up?

Thanks