“I highly doubt that.”
We will know when more facts make the news, but I can see where they would be a good idea. If it was indeed a copy of the Turtle. One of the downsides of it, and the much later confederate sub Hunley was the fact they could not stay down very long at all. At least no without a snorkel. I do wanna see more on this interesting story.
Air tanks, yes. Not oxygen tanks.