I-201-class submarine
 The I-201-class submarines (伊二百一型潜水艦 I-Nihyakuichi-gata sensuikan) were submarines of the Imperial Japanese Navy during World War II. These submarines were of advanced design built for high underwater speed and were known as Submarine High speed-Large type (潜高大型 Sen Taka-Dai gata) or Submarine-High speed type (潜高型 Sen Taka gata).