Do you mean the base attaching to the floor? If so its just stainless steel deck screws... they screw into the floor and can be easily removed.
I have seen several people use thick plywood underneath it in a pattern that matches the base plate to lift the seat up a little... so long as you use decent quality stuff and paint it with resin it should be good for a good few years; witht he bonus of it being a cheap solution and removable come boat sale time.
You could even dress it up with some vinyl to match the boats interior if you have a spare hour and $50 to burn 8)
Alternatively, it's a pretty standard mount for the seat... could be worth finding a bolster seat like in the 1800 SR3's - many boats have them... so pretty much any seat with similar upholstery would work... if you could pick one up cheap (from a wrecked boat for example) this could be an option.
Now if you really had alot of spare time.... and wanted something pimping... you could buy a linear actuator and put a switch on the dash to make the seat raise and lower electronically...