[Macgregor the Hammer]

I have read through a considerable amount of the material you shared and it has made it’s way into my Captain’s Book. Thanks again!

I doubt if I will give up using the reference book. I disagree with your assessment of the use of the Reference Book. I’ve seen a considerable amount of pictures of both German and American Captain’s with the reference book in their hands, looking through the periscope. We all have read books about submarine warfare in WW 2 and the one’s I’ve read discuss the use of the reference book. The Office of Naval Intelligence rated the confidence of each image and it’s dimensions . The ONI was constantly updating it as new information became available. The German Abwehr did the same. Disinformation was created on both sides by camouflaging mast height. A great deal of money was spent on developing the stadimeter, precision telemeters, the RAOBF, the omnimeter, the attack disc, target data computers, etc to just be part of the scenery in a sub. The tools are useless without ship data.

The Reference Book is not the end all and be all, just one of many important tools available to a sub skipper.