Yeah, but he's only lining a van ................. not building a boat.
In my opinion WBP ply is more than able to do the job.
my thoughts on it are, if your going to have set floors then WMP ply will not last that long, but then again, as i said, i would go with protectakote instead of ply
though another option if you have the time, leave your existing ply down and coat with fibreglass ( the floor will need the fibreglass stranded matting down, and 12" up the sides of just the paint, now that would last forever and look great