I appreciate all of the responses.
1) Yes, I will definitely look for leaks. I was in big water (big waves) the other day, but it sounds like the boat should not be taking on this much water even under those conditions.
2) @pro10is - My drain plug is not at the lowest point on the boat. I found this pic on the web - it seems to depict what you are describing:
This looks like a great design!!
HOWEVER, my boat is considerably OLDER. The drain plug is on the right side of the stern. The boat most definitely does not drain water when level.
Quite frankly, I'm befuddled by the type of logic or complete lack of logic that this design implies.
MOST IMPORTANTLY, it is not clear to me how to drain water from the boat safely without damaging the boat. Roll it over on its right side, plant the stern in the ground, and lift up the bow. But how do I keep the rudder from getting damaged during that process?
Do I need to remove the rudder to safely drain the boat? That seems ridiculous.