US Navy Regulations best manual 1920 book

Hardback reference book updated in 1941. I know, I know, you're thinking of Dec 7, 1941 and how this manual probably changed significantly after Pearl Harbor. Probably did. I find it interesting to see a manual this thick best loaded with seemingly every detail needed to defend the men and fleet yet still we had Pearl Harbor. Book is 8 1/2 x 6 1/2 x 2 1/2" thick. Book is near fine condition with perfectly clean pages Spine tight and orderly except on front board where it is a little loose (I didn't glue it).