My new old boat is missing the drain plug. I stopped at the nearest boating supply store and they suggested a threaded brass plug, but it is very much not right. Can anyone point me in the right direction for information? Sure I can take a ruler out and measure the hole, but I'm hoping for something a little more accurate 
1981 Four Winns Marquise, 160 (120 hp)
1981 Four Winns Marquise, 160 (120 hp)