cockpit plugs HA18

[KonTiki]

I recently purchased my HA18 and I'm readying to launch.
I have 3 plugs hanging on the aft wall of the cabin. One rubber with a brass handle and 2 others, rubber with rope handles. I see the cockpit drain hole directly in from of the cabin entrance (assuming the brass handle one goes here), and another hole just in front of the outboard motor well. I and curious what the 3rd plug is for. Also, when should these plugs be in place? and when should they be removed?

plugs in place while under way, and removed while docked??

[spudsailor]

Depending on the vintage of your America, you might want to plug the cockpit drain while underway if it drains directly into the centerboard trunk.  On later years (possibly 1975 and later) the cockpit drained thru a thru hull on the starboard side, an improvement as I have had both and the side drain is better in many ways.
If you have a sink you might want to stick a plug in it while underway also.

[KonTiki]

Thank you!
I have a 1972 without a sink