I like Wildmans idea about the large piece of aluminum in the deck and glassed over.I gave a lot of thought to a similar mount,but it was going to be a round aluminum plate bigger than the pedestal base placed on top of the deck floor with several countersunk screw holes in it.
I figured it would have given it a much more secure base and far far less chance of pulling out(been there done that).The glassed in plate mentioned, would be even better
On my Tsunami,I really wanted to be able to store equipment and other stuff under the seats,so I decided to somehow not use pedestals.We had a 150qt fish cooler that we wanted to slide under the stbd. seat,and other stuff under the port seat.
My buddy came up with this design,and it works good.Even with the weights of our fat butts, 250lbs ea. they are as solid as a rock.
I don't like the seats though and plan on replacing them at some point.
With the mounting points being in so many places there is no chance of the seat pulling out.
The upper mounting points on the liner are 1/4 -20 machine screws threaded into stainless inserts that we installed in the liner.(similar to a threaded pop rivet insert,only an industrial product)
The seats height is a wee bit to high,but not a big deal.The foot rests are at a good height for our feet,and if we're sitting sideways we can place our feet on the cross bars on the seat frame.
Here's a few pics.Not sure if it's visible,but the big cooler is under the seat,and at the end of the day we can place a lot of equipment under them and drop the rear curtain(last pic.)and out of sight of some of the prying eyes of the marina rats that like to steal easy to reach equipment.
