Outback Scupper Plugs

Hi All, New to kayak fishing, and this site. Just got a Hobie Outback, have a question about the scupper plugs. I understand the purpose of them, and how to use them. What I am looking for is; does anyone know or can someone measure the holes and let me know their size? I do not have my calipers with me. I have eye balled them, and I come up with the two in the back at 1 1/8, and the one under the seat at 1 5/16, am I close? Sure I will have many more rigging questions in the future.

Thanks for any help provided