Drains

[Blue_Runner]

This question is about the 3 drains in my 72 that drain water from the 2 fish boxes and the cuddy hold area.

Question is, can I confidently drain water through these holes without rotting the inards of my boat? It doesn't look like they are plumbed, rather they just let the water fall down on the outer shell and back to the underside drain.

Or, should I plug the holes with plugs and try not to get any water in there?

Thanks guys,
Blue