Replacing a seat in a 1965 14 foot Crestliner row boat

[Coach]

One of the bench seats have rotted away and I need to replace it. It was 3/4 inch plywood covered in a fake wood liner. What is the best way to replace this? Could I replace it with some kind of plastic instead of wood? Where would I find it? Thanks for any info.

[Slyster]

I replaced mine with regular plywood.. but after I cut it to shape and carefully painted it and applied a few good coats of glossy polyurethane. Perfect 4 years later.