For what it's worth, I made this for the rear deck.
It's an extra boat seat I had left over from another boat. It's mounted on a swivel base and a short wood pedestal. It's all attached to a 3/4 plywood base sized to fit down in the rear deck. Nothing bolts it down but the large ply base seems to make it quite stable.
That all being said --- it hasn't been tested it on the water yet. That will happen in early July when the grandkids will be down for a visit and we'll all be up at the lake.
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