Sundew, my 1979, hull number 249 has the same and I once wondered about their purpose. I would advise against plugging them, even temporarily, for obvious reasons. Additionally, what if you left the boat for a time with the plugs fitted? Rain water could eventually fill the cockpit to hatch level, then leak into the boat. To avoid back-fill when the boat is heeled over and when close-hauled, the following should be done: Buy new reinforced hose, but longer. Route the port cockpit drain to the starboard transom skin fitting and vice-versa for the starboard. The hose needs to be long enough to prevent it from kinking and therefore restricting the flow.
Regards,
Nic
Eur Ing Nic Fieldhouse BEng (Hons) CEng MIMechE GradIIMS
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