I purchased my boat without the drain plugs installed, to save someone the time of running to the store multiple times here are the sizes that fit:
- the outside hole below the transom: 1/2"
- the inside hole on the back of the cockpit: 31/32"
The plugs are made by Moeller Marine, pretty good quality, turn-and-lock type, $3.15 each.
I took the boat on the first sail this year and things were as dry as when we left. There was not much of wind last night, but the sunset on the Diamond Lake, IL was spectacular.