Scuppers
 

What you've got there is a " duck bill check valve". There is a company that
makes them. smallest is 1/2". It looks like the nozzle on a Woopie Cushion.

DJ

Oh that's just great! My wife will like 'em, Every time I go to the transom and check the baits it will sound like I shit my pants :eek:

You will only have to worry if you have flies buzzin' your
azz after that distinctive wet fluttering sound....:eek:

Anyone ever think of using a condom?...

Fellowship suggested that in his original post! Great conversational value, but I don't think they'd hold up too well! Even the thin medical grade nitril gloves you can buy cheap at Wal-mart (<$10 for a box of 40) hold up pretty well, much better than latex.