To your last question: the nature of having to attract clicks means youtube creators have to choose reductive titles that tease some particular nugget of information that's going to be discussed, but it seems pretty clear (at least to me) that the intent of this video isn't _just_ to answer that question, and that he expects that his audience will also appreciate a slice-of-life experience of him interacting with the crew and understanding what life is like on the submarine in broader terms than just how they get air.

With respect: if all you wanted was the answer to that question and nothing else, Googling produces it much more quickly than you'd likely ever get from a video, and you might just not be the target audience here. I personally enjoyed the whole series as-is, and it seems from the YouTube comments like many viewers did as well, but obviously YMMV.