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- Iguape (Brazil): 150-ton minesweeper
- Iku-Turso (Finland): 716-ton submarine
- Ilmatar (Estonia): gunboat
- Islands Falk (Denmark): 760-ton fishery patrol vessel
- Itacuruca (Brazil): 210-ton mine layer
- Itajahy (Brazil): 150-ton minesweeper
- Itapemirim (Brazil): 340-ton mine layer
Read more about this topic: List Of World War II Ships Of Less Than 1000 Tons