Here is a wonderful story of Justin Beckerman, an 18-year-old high school student in New Jersey, who is in the final testing phase of designing and manufacturing a fully-operational one-man submarine. Thanks to Irwin Bryan for passing the story along.
He is one of many over the years.
A few years back was in contact with a man and his wife in Texas that were building one and it was huge.
Lost contact with him so don’t know is he survived it?