The 15 torpedoboats of the Ariete class were the largest class of ships captured by the Kriegsmarine after the Italian surrender in
September 1943. None of those ships were already completed at this time and after completion all were part of the 10th TFlottila, and used for mine laying, escort duty and coastal defense.

The Rigel  was captured by Germans in advanced condition of fitting out, it was completed, renamed to TA28 and commissioned on 23.01.1944. From the last day of March on 1944 this unit was in the 11.Sicherungsdivision, 2.Geleitflottille and took part of the bombardment of Bastia on 01.03.1944. Operating at the Italian west coast, it was destroyed by bomb hits while being maintained in a dry dock in Genoa on 04.09.1944.