Here are what the holes look like from the inside.






Now its time to install the new 1” thru-hulls. Have someone wait in the boat with a large (12”) crescent wrench to put the nut on the new intake and tighten it down, while you are under the boat. Put the 3M 4200 on the flange and put each one in and have your friend in the boat tighten the nut from the top. I put the 4200 on the intake flange and the nut flange just in case. Use your finger to wipe the extra 4200 from around the fitting like you would when caulking a bathtub. Take a rag with you to clean up the excess 4200 from your hands. Then let it dry for a few hours if its hot out or a day if its cold.