The first successes were achieved when Hardegen sank the American tanker Muskogee (7,034 GRT) on 22 March and the British tanker Empire Steel (8,150 GRT) on 24 March.
Kesuksesan pertama diraih ketika Hardegen menenggelamkan tanker Amerika Muskogee (7,034 GRT) pada 22 Maret dan tanker Inggris Empire Steel (8,150 GRT) pada 24 Maret.