Need Help

[BASSX08]

I want to take out my middle seat in my boat and make more floor space and but in a livewell but it is ribited in and i know i have to drill them out and there are some below the water line of the boat how or what do you seal them with it is alum boat heres a pic

[J_Zink]

If your boat is anything like mine, the seat is actually riveted to brackets which are riveted to the boat hull.  Drill out the rivets that attach the seat to the brackets and then cut the brackets down with a saw or die grinder.