Can you replace a fiber glass boat floor with a wood floor?

could you just provide yourself a cheap and easy way to slap a new floor surface in, yes. would a sheet of plywood work (1/2" min, 3/4" would be better), yes. would a sealed with deck products piece of wood last, yes. but the real questions, if the fiberglass is failing in one spot, what condition do you expect it to be in elsewhere? if the floor cant support your 150-300 lbs of weight driven force, how much force from the motor can the transom handle? fiberglass, 30 years is OLD. wood is used in fiberglass, even a well cared for boat will see a lot of moisture in 30 years and that moisture will rot and weaken the wood. buying used boats, ALWAYS have a qualified marine mechanic perform a mechanical inspection AND test drive it on the water. lots of poeple out there trying to sell boats with minor or MAJOR problems who are fully aware they can usually hook up a hose, start it and let it idle for a couple of minutes and have somebody buy it on just that. lots of minor or MAJOR problems that cant be noticed like that...... had you done what is required to protect yourself, no way you would of bought this boat. return it if possible. or put the bare minimum in it and always wear a life jacket, you might get a year or two out of it.

Fiberglass doesn't rot if U cut it open U will find plywood under it. As if all fiberglass it would be to heavy. Yes U can replace it will wood but seal the bottom and glass the top.

You can but it will be VERY expensive, I would just patch the fiber glass

The floor is a structural member, and as such must be repair to original specs. It is normal in production boats to be fairly blase' on internal structure fit out, with floors often not even being glassed on the underside (or coated with anything at all). Any repair you do will if done right be far superior than the original. When you cut out the rotted and soft section(s) you can expect to find far more than a little job, as the damage is normally profound by the time it is clearly noticeable externally. You can expect to replace supports, stringers, gusset braces and a large amount of ply - and if the floor skin is not in good order you will need to fully glass the top and underside of the new section - it will take some dollars and a commitment of time and effort to do it right. You could just drop a section of ply over the soft bit and take a chance, but the damage will only worsen and render the boat completely unsafe in the end.

This is old memory's replaced a lot of floors some good some bad some OMG,If you plan to just use the boat a year or two save yourself some money and pull the seats and carpet if any and drop a half sheet of 5/8 in ply wood in the floor trim it as to fit as tight to the sides as you can do not put a screw though the hull did this too many years ago use short screws just long enough to go though the plywood and stay off the edges as the hull is thin as far as the distance to the outer hull.place the screws just a hand full right though the mid section of the plywood and drop a cheap carpet over it and put your seats in and hit the water.You can seal the edges of the underside of the plywood with a good tube of exterior sealer that will keep the water for a while from getting under the plywood patch and rotting it but it still will take a while.Seen this done for 30 years and done it myself on a boat that was a fast fix and see folks running boats for not seasons but YEARS with a bad floor and just a sheet of plywood dropped right in and carpet put over it to hide the fast repair>as for cutting it out yes you can do that easy enough trying to pull the whole floor that's a job and a half.But if the area is fairly to the middle of the floor area you can jig saw it out and use 2x2 or even 1x2 and use those as i inside frame around the inside of your area and drop in a new section of floor and calk your edge if you decide not to lay glass over the patch or do not know how just seal the edges and put paint on it a oil base and let it go it will last a long time just the same that would be your better fast fix given that the floor feels solid everywere else if the floor has multi soft spots the drop the sheet over the floor would be your best fast fix and run the hell out of it come end of summer fix it right keep it the way it is and run it again next summer or sell it off and look another.Another thing to if your engine is good Hulls with no power are a dime a dozen your engine is the money hell run it but this summer look around for a hull sitting good floor BUT NO Motor means cheap even if it is sitting on the ground if the size is right you got your trailer to use swap over from your boat what you need and junk yours out but in the mean time while your looking your boat will get you out and wet have fun..

The fiberglass on the deck is just a layer to cover it up, the deck is plywood and the rot starts from under the floor. There might be floatation foam under the deck that is saturated with water...I bet that the stringer(s) underneath that deck ar rotting also......you better check the transom also as it must handle the weight of the motor and all the forces while under load.! Poke on the transom inside the boat with a pointy screwdriver on the lowest point possible, don't fool your self while doing that... it should be rock hard. Tap on the outside around the drive or outboard, if it sounds dull..bad news. Quite common on a 36 year old boat tho, I replaced it all on my `78 5 years ago. Good luck!

As long as you bond in enough support I don't see why not.