The first true military submarines weren't introduced until WWII? Negative. Germany alone had almost 50 subs at the start of WWI and nearly 15 different types from minelayers to littoral attack subs. Very disappointing to see this misinformation being spread and unfortunate for the viewers who don't know any better.

The newest submarines do not use "the latest in technology, like sail-mounted dive planes.." Those have been deleted since the Seawolf class, (which is no longer being built) in favor of retractable bow planes now being set into the hull itself.

Between the b-20 being replaced by the b-21 and the ohio with the columbia, things are going to be nuts. Both of those legacy systems are still top in the world, and have been since introduction. Both of these systems are going to be crazy.

I've noticed that these videos are either right on the money with the info they provide or just completely wrong. Also I've noticed they start out talking about one subject or a certain piece of equipment and usually end up talking about a different subject altogether by the end of the video

I gave after the first minute, breathtaking lack of research especially since the first military attack by a submarine was during the American civil war and it was Germany during the great war who perfected their use.