Ocean Kayak Scupper Valves M - 2-Pack
Here's what other sites are saying:
Pop the medium Scupper Valve into your Ocean Kayak's hull and put an end to the soggy rear. Pull em out when it's time to port-out and those scupper holes can do their duty of draining any water that decided to stow away in your boat.
The Scupper Valves from Ocean Kayak take the whole concept of a scupper to the next level.