Marine Seaboard. Mercury Gray. 54" x 96" x 1/2". Provides superior performance where water, UV exposure, and other harsh elements are present. Unlike wood or metal alternatives, our marine building materials will not rust, corrode, rot, delaminate, or splinter. With superior scratch resistance, stiffness, and packages, this seaboard is ideal for outdoor cabinetry, marine furniture, signage and recreational applications.