Broken "spotter" seat on 93 SN

Gentlemen - I was able to take my new (to me) 93' out for the first time this past weekend. The boat performed wonderfully. I am absolutely thrilled with my purchase. However, I have a couple of small things that I could use your advice on:

1) The hardboard support under the spotter seat is broken. It looks like a bad design to me. The cushion (and the hardboard support that it is attached to) anchor to the "lift up" portion. There is no support under the last 10" or so of the seat and someone (before I bought it) broke it. Could have been Two-Ton Tessy for all I know. At any rate - Has anyone else had this problem? If so, do you have a recommended material to replace (or support) the existing hardboard under the cusion? I may need to upload a pic if this does not make sense.

2) The gas tank vent. The vent is in the middle of the boat, right behind the rear seats. Is it normal to smell fairly significant gas fumes when the boat is sitting on the trailer after use? I have no reason to believe that I have a gas leak; however, the fumes coming out of the vent seem stronger than I would have guessed they would be. However, I have no context whatsoever here.

Thanks in advance for your help!

Marine grade ply is not needed unless youre building a boat hull... the last place I would use it is for a seat base!

If youre looking for a quick and easy solution, treated ply of the same thickness as the original base would work. A better solution would be to use a composite like was originally used. It is not common to hear of these breaking.

I for one, would like to see pictures. I have looked at the '93 Ski Nautique observer seats pretty closely, and emulated that style on my '90. I cannot think of any overhang that approaches anywhere near 10" though, so Id like to see what youre looking at. Perhaps your use of "SN" means Sport Nautique (this is not the common use)?

All great suggestions, gentlemen. Thanks! I'll report back what worked.

OK - Marine Grade was an overshot. Pressure treated would work fine.

Here's a shot I took of my two 1993 observers seats. Apparently the one on the right is the correct composite material. That's the tree boat. The one on the left is plywood and came from my ski-school boat. I'm guessing this was re-upholstered at some point in the past as the vinyl material for the seat is a very different type of vinyl. I'd sure love some more history about my hull....

You have to take the upholstery and foam off the board to glue it back together with the PVC cement or the PVC cement will eat up the foam and vinyl!