Humidity, salty water splash, and seasonal weather swings degrade marine wall systems. FRP swells, metal fasteners rust, and drywall disintegrates. When evaluating FRP vs. PVC wall panels for marinas, PVC marine wall panels handle moisture better. While FRP withstands water on its outer surface, its reliance on backer boards poses a serious threat in marine applications. Solid PVC wall panels offer 100% water resistance, eliminating moisture damage.