title: Hai (midget submarine)
text: # Hai (midget submarine)
  
  Hai (shark) was an advanced model of the Marder-class midget submarines created in Nazi Germany during World War II and operated by the K-Verband. Its prototype performed poorly during test runs and therefore no other boats were produced.
  
  The Hai was 11 meters (36 ft 1 in) long and its length allowed for larger batteries, giving it the maximum speed of 20 knots (37 km/h; 23 mph) under water. In addition, the Hai could remain under water for up to two hours.
  
  