Lumber type for Jon boat

Recently found out that pressure treated lumber reacts to aluminum and low an behold that’s what I have. Being a metal guy I have no clue about carpentry and wood types/grades.
Is wood either pressure treated or untreated? I keep reading about pressure treated wood, treated wood, and then untreated wood. I’m not sure if treated wood is the same as pressure treated or something different entirely.
Basically what should I ask for when I go to Lowe’s or Home Depot.

Well, if you are a metal guy, why don't you use metal? Aluminum is the best alternative. Stay away from any wood that has been treated with a metal treatment like copper. Pressure treated wood is usually treated that way. There is another treatment for termites but, not rot. It might be okay, not sure. Usually we like to use untreated wood and then seal it with a good sealer like epoxy or the old timers formula.

Well I would but don’t feel like spending the cash on a sheet of metal. Looks like I’ll get the untreated and coat it in oil based paint.

For plywood you will want to use and exterior grade plywood, It should be stamped on the board. Some plywood is made for furniture and cabinet, it is pretty but, won't hold up to getting wet. Most exterior plywood is made from pine. If you can find the sign board, it is the best, Not sure what they call it but someone on hear will probably chime in on that.

Maybe do a search on sign plywood.