Inside drain tube

This was done without metal: I created a fiberglass tube by wrapping glass around PVC. I didn't coat the PVC in any release agent and it was a bear to remove.

The drain tube is angled so water cleanly drains with no water remaining in the bilge.

The backer plate is 1X4 hardwood shaped to provide good drainage.

You can also see the drain plug. I cut down the arms on the twisting part so it would clear the hull when twisted. It is tethered with 100 lb braided fishing line.