I actually saw that one but it is not the sub show I was referring too.
This show is called "How hard could it be"
They build a deep diving remote controlled sub. I have not recorded it yet so I just have the TV info to go by.
I will say the redneck submarine one was a good lesson on how not to build a submarine. The to guys inside were almost killed as the design was a death trap.
But it did work for a while.