Auto mechanic Frank Russell of Biggleswade, England spent two years building a submarine in his backyard. He did it, he said, so that he could find the "lost city" of Atlantis. He described the construction of the sub in an article distributed by International News Service (Dec 1949):
My job is that of a motor mechanic and these craft that I build are purely a spare time hobby. Thus I have to get on with their construction as I can afford it; a few shillings or a pound or so at a time. Believe me, this method is exasperating and heartbreaking.
Practically all the parts have been cut, filed and even some of the holes drilled with ordinary hand tools, though I did manage on several occasions to borrow an oxy-acetylene cutter and an electric drill.
I have built this craft entirely by myself except for some of the more tricky points of welding on the hull. This was done by a friend, who is a highly skilled factory welder.
This submarine has been built entirely out of second-hand steel plates and scrap from local yards. Oxygen cylinders, motors, batteries, and the like are all from government surplus sales. The only new items are the glass observation ports and some rivets and bolts.
The launch date for his sub was November 4, 1950. Unfortunately, I can't find any reports about the launch, but I'm assuming he didn't find Atlantis.
And I'm guessing he may have been pulling everyone's leg about wanting to search for Atlantis, because eight years later he was back in the news as the perpetrator of an elaborate UFO hoax involving a "do-it-yourself space ship made of wire, silver paper, clockwork and a couple of flashlights." So it seems that he was a bit of a practical joker.
The Eagle (Bryan, Texas) - Nov 8, 1950
New Castle News - Oct 7, 1949
The Decatur Herald - May 28, 1958