The longevity of a bathtub tray relies heavily on how the tray is manufactured and what materials make up the hardware and body. If it's crafted with water-resistant materials like varnished bamboo, acrylic, or stainless steel, it won't wear as quickly when exposed to moisture. You can prolong the life of your bathtub tray by coating it with an outdoor stain or polyurethane to add more water resistance. It's also advisable to dry it off after use to avoid any mold or mildew on the wood, or any rusting on exposed metal hardware.