This is a mistake that many people make without even realizing they are doing it. A boat floor is not meant to have nails in it and doing so weakens the structure. It also creates spaces where water can get deeper into the boat, the floor, and other areas. Even a gap as small as a nail head can wreak havoc on an otherwise healthy boat so when replacing flooring, avoid nailing altogether. If you have no other recourse, use wood putty and epoxy over the nails. Doing this simple additional task will save you a lot of time and money down the line, since the putty or epoxy will effectively cover the hole created by the head of the nail. [links]