Interesting, I was talking to a tenant about a submarine that could travel through the water as fast as a jet. I told him if I were to build it I would make a double hull with the outer shell having millions of small holes in it that would allow air bubbles to escape creating a slipstream for the submarine. The pressurized hull would get its oxygen from the water by running it through the engines creating a steam or electrolysis creating hydrogen. The submarine would be propelled by ajet engine or turboprop. Took me all about a minute to figure it out.
Just now all the sudden I see this article and I wonder how long it took them to figure it out?

https://luxurylaunches.com...