Bass Boat floor drain replacement hardware ?

Ive recently rebuilt my boat .. when I got the bot the floor drain in the cockpit was missing, just a hole where the drain once was .. Ive looked and looked can't find a proper replacement drain. my floor is 1/2 thick with layer of glass on bottom and 2 on top.. I want something that looks good but the plastic or pvc to slightly extend below the floor so rot cant happen agin thru the floor drain. Every floor drain I find is 4" diamater hole and is maybe 1/4 inch of the plastic would extend down into the hole. I know what Im looking for must exsist just cant locate it want 2 -3 inch diamater hole and a 3/4 to 1 inch or more to extend down into the hole .. any help would be appreciated