The 30th Flotilla was founded in October 1942 under the command of Kptlt. Helmut Rosenbaum. The boats reached Constanza after a transport over land and canals. The operational area was limited to the Black Sea. Its history ended in September 1944, when the three last Flotillas boats U-19, U-20 and U-23 were scuttled on 10 and 11 September 1944 near the Turkish coast. – "Uboat.net". The Flotillas – 30th Flotilla. Archived from the original on 20 November 2009. Retrieved 13 November 2009.
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The 30th Flotilla was founded in October 1942 under the command of Kptlt. Helmut Rosenbaum. The boats reached Constanza after a transport over land and canals. The operational area was limited to the Black Sea. Its history ended in September 1944, when the three last Flotillas boats U-19, U-20 and U-23 were scuttled on 10 and 11 September 1944 near the Turkish coast. – "Uboat.net". The Flotillas – 30th Flotilla. Archived from the original on 20 November 2009. Retrieved 13 November 2009.