I am trying to replace the seats on a 2000 Sprint bass boat.  The center bottom cushion comes out and there is a screw which is holding down the seat base.  My issue is the back rest.  It appears to have two screws which go in to the boat.  I can not remove the cushion part on the back to access the screws and the other side of the boat base has the gas tank preventing access.  Has anyone ever ran across this situation?

I would think you would have to take the seat base out.  That is usually one piece of molded plastic and the back and cushion are attached to it.  The back is screwed into it, the seat is screwed into the boat at under the cushion and then the cushion is screwed in.  As you have already found out, there is a big old fuel tank right behind that piece of fiber glass so don't go trying to poke hole or put screws in it.  Also be very careful with the part the seat is sitting on.  I have seen L shaped tanks in them and part of the tank was under it also.  Screw the tank up and a lot of times, the cap has to come off to get it out.

You are correct that the gas tank actually goes under the seat as well.  This is certainly a job I would have that within my wheel house but I don't want to screw the gas tank up.  Current seat has screw in bottom cushion as well as seat back.  This is looking like a job that I will outsource.