Marine Ply Alternate is of an even better quality than BWR grade, and used in conditions where the plywood is sure to get a prolonged exposure to extreme weather conditions such as even being submerged in water. It is the ideal choice for building ships, boats and other such marine applications. What makes Marine ply so strong and water resistant, is the use of excellent quality wood veneers for making the plywood, and the use of unextended (meaning undiluted) phenolic resins. The resin Phenol formaldehyde is in fact a synthetic plastic resin, and that greatly increases the water proofing quality of Marine plywood. On the other hand in BWR grade ply, extenders are added to the resin, and it is diluted before using it to glue the plies together
It is much more expensive than standard plywood. There are few international standards for grading marine plywood and most of the standards are voluntary. Some plywood is also labeled based on the wood used to manufacture it.
Moisture resistant – it can resist moisture and humidity
IS standard specification
Wide range of sizes, shapes and thicknesses