17ft Aluminium boat transom rebuild - advice needed

[xoibsurferx]

Hello everyone. I have an older unknown brand/model Aluminium boat that’s 17ft with an older 1984 Johnson 25hp outboard. I’m replacing the transom board due to it being rotten and desperately needing replaced before I can take it out again.

What type of wood should I use? And where do I get it? Seems like there’s a lot of marine wood options but some are expensive and about worth as much as the boat.

Also in the pictures you can see the transom has seen better days and I’m concerned about the stress of the weight of the motor. I know replacing the wood will be a major help. Is that all I will need to do to bring it back to life on the water safely?

thanks in advance!

 

[oldrem]

I used ACX plywood for mine. 2 layers of 3/4" glued together with PL then treated with the Old Timers Formula followed by 2 coats of spar urethane (or spar vanish depending on which version of the OT you use). Should outlast the boat