The original source is in Chinese, so I don't know too much about this homebuilt submarine, other than it was built by a Chinese farmer. On inspection, I doubt it will even submerge; it is probably simply a boat with submarine decoration. I hope I am wrong.
It appears on a site with a collection of other homemade vehicles, including a UFO.
I really find these homemade toys and trucks to be lovely. Yet, I know every kid with one of these boy-built toys would trade it in a second for a mass-produced plastic truck. This example comes from the Solomon Islands. I found the picture on the UNICEF Childrenssite.
Throughout the world kids have always made their own toys. Toy trucks are popular. These you push with a stick to make them go over rough roads. Being a truck driver is what a lot of kids would like to grow up to do. Note the cool cargo.
This picture of boys in Mozambique came from Travel Images.
This one is from Southing, a blog of two Danish travelers, Helle Gammelgaard and Mario Travaini.