[red-beard]

Originally Posted by Baz

Quick update - current thinking is to go with Aluminum standing seam panels. Painted white for optimum reflectivity....We'll see.....right now though the aluminum sounds like the best choice given my proximity to the coast.

https://www.englertinc.com/blog/steel-and-aluminum-two-great-metal-roofing-materials-each-have-their-strengths/

Check the material selection. Some forms of aluminum are attacked by salt air more than other. If the material is 5052 your should be fine.