Marine Plywood is a completely waterproof plywood, that has been specifically manufactured for marine applications. Unextended phenolic resin is used for bonding the plies together. Unextended means undiluted Phenolic resin is a synthetic plastic resin made from phenol formaldehyde and it makes Marine plywood completely waterproof. Marine plywood is used for building boats and ships, and any other applications in which the plywood is sure to get a large amount of exposure to water. Marine plywood is of Exterior grade and meant for extreme exterior uses. Its also better than the Exterior grade BWR (Boiling Water resistant) plywood that is used for making kitchen furniture. It is a lot costlier than Commercial ply. It is much stronger than Commercial grade plywood because of the superior wood and glues used in its manufacture.