Need help fact checking

[McBeck]

I have put together a proposed intro for my video on U995.

Can you help with fact checking and fill in the blanks marked with XXX?
If I got something wrong, it would be great if you could link to a source

Before we enter the sub, I would like to outline why this submarine in significant. The U995 is a type VII German WWII submarine. During the war this type of submarine formed the backbone of the german submarine strategy to stop supplies coming into Brittain from the US. This campaign was called the Battle of the Atalantic and continued for the duration of the war. During this time the allied used a convoy system of ships sailing from ports in the US in through the Western approaches to Britain. The german navy in turn deployed a wolfpack tactic where submarines would patrol west of britain, with the goal of finding these convoys. When a submarine found a convoy it would contact Command with location, composition, speed and course for the convoy, but the submarine would not attack, but shadow the convoy. The information about the convoy was relayed to other submarines in the area so they could coordinate an attack – hence the name wolfpacks. This type of submarine would have a crew of xx men sharing a cramped space for months at sea – needless to say it was not for the frail of mind. XX of them was built out of xx in a total of type II, VII, IX and XXI. Of app XXXXX german submariners, XXXX did not return during WWII.

A small disclaimer : The U995 was in service in the Norwegian Navy in a period after the war, so there may be items which are not original ...now lets see how the submarine looks from the inside...