That is an interesting question and I don’t know the answer, but the one who does know and has actually built one is Tao Xiangli. Let’s take a look. 😀
Not having finished primary school and having built a personal submarine, with second-hand scrap… priceless. Well, yes, and indeed Tao Xiangli spent a total of $4,366.
The submarine he created is capable of diving up to 10 meters, and only has the capacity for one person. And regardless of the shape or design, Tao Xiangli was able to introduce pressure gauges, oxygen tanks, a front light, video cameras, and a television monitor. He doesn’t have a fool’s hair, he has the hair of pure intelligence. How’s it going!
Source: Sky News