Re: 21 ft party barge
To do it right you need to remove everything off the boat: furniture, side rails, console, trim...then rip up the old carpet which can be a real nightmare. But once you get down to a surface you can work with the actual gluing and laying the carpet is easy, that only takes a couple hours...plenty of write-ups on how to do that.
Be careful though ripping up the old carpet, because if your floors are getting old the wood might be starting to delaminate and you will be ripping up wood along with old carpet and will wind up needed to replace the floor....but do it right and you will be happy