I'm currently in the process of writing a sci-fi underwater monster book, and I need to get specs for a commercially built two person submarine that can reach speeds of close to what a Russian Akula class can do- around 35 knots.
This small submersible needs to be able to fit at the back of a yacht. I've looked at the other personal submarines on the market like the Orcasub and U-Boat Worx Hipersub, but it seems they can only attain a maximum speed of 6 knots underwater. Is it possible to build a private submarine similar to these two commercial models yet can go faster? What kind of engine would you need? Will it be electric, Diesel powered or something else?
If its not electric what would be her maximum depth?