Marine plywood could be graded as becoming compliant with BS 1088, that is a British Conventional for maritime plywood which is:710 is Bureau of Indian Expectations (BIS) for marine grade plywood. You can find couple of Intercontinental requirements for grading maritime plywood and many of the requirements are voluntary. In https://jaidenplfat.bloggip.com/23869418/detailed-notes-on-birch-plywood