...but if it's a proper gunwhale-to-gunwhale thwart that you typically see in most dinghies, taking it out would seriously compromise the structural integrity of the whole boat. One good bump against the jetty and it would fold up like one of those alfoil pie tins!

It may also be part of the flotation of the boat.
Sometimes the underside of the seat is filled with foam and this assists with the floatation if the boat is swamped.

I did the same to my Savage Gannet (13ft) without any problems.

My initial concerns were about the structual strengh provided by the gunnel and seat combo.

All proved to be unfounded. I had tthe boat for 5 years without the middle seat and all was still sound when I sold it.

We did 4 trips to Steep Point in that time too.

The removal made the boat a better craft for it........more usable space.

I also put in a carpeted floor.

 Took out the middle seat on a savage gannet, put a frame in the floor and put check plate down...two pedestal seats up the front worked a treat...made it a much better craft for our use

+ 1 get rid of the seat and put a marine ply floor in,did it with my little 12 ft dinghy.Ran it it for 8 years no probs sold it and have seen it still getting round,as said above makes them a much more user friendly craft.

 Thanks for the input guys.I want to put a floor in it so will put a frame in and then wood floor with carpet.When you guys removed the seats how did you cover/fill the holes as the seat is rivetted so wil be a couple of holes.

I just put some new rivets in the holes,instead of carpet i painted the ply then flicked a bit of beach sand on it ,instant non slip.depends how flash you want it to look .

I had an old tinny with the middle seat removed and it didnt last long before major cracks appeared.  Newer tinnies may be better built?