a deck on what?
if its a fiberglass boat, after you deal with the stringers and transom, then the deck is last. (boats rot from the bottom up)
go here https://forums.iboats.com/forum/boat-restoration-building-and-hull-repair.40/
read links 14, 15, 18, 2, 3, 4a, 4b
if its a pontoon boat...