BS 1088 and BS 6566 are British Standard specification grade for marine plywood. To be qualitfied as marine plywood, it must be produced with untreated tropical hardwood veneers that have a set level of resistance to fungal attack, use WBP glue, no core voids, and controll thickness and number of plies. The face veneers must have a solid surface without open defects. BS 6566 standard is similar to the BS 1088 with somewhat reduced quality.