|Shipyard||Blohm & Voss, Hamburg (Werk 282)|
|Ordered||12 Jan 1916|
|Launched||15 Jul 1916|
|Commissioned||14 Nov 1916|
|Successes||30 ships sunk with a total of 42,006 tons.|
6 ships damaged with a total of 27,410 tons.
2 warships sunk with a total of 2,500 tons. (View ships hit by UC 66)
27 May 1917 - Bombed and sunk on May 27, 1917 north of Round Island, Isles of Scilly, by RNAS Curtis H.12 flying boat No. 8656 piloted by William Anderson. A corresponding wreck was located in 2009. 23 dead|
Loss reassessed in 2013 by Innes McCartney. Anderson was awarded the Distinguished Service Cross for the attack. He would later become an Anglican bishop.
Previously recorded fate
Sunk on June 12, 1917 by depth charged from HMT Sea King, followed up by the explosion of her own mines at 49°45’N 5°10’W. This explanation requires an excessively long patrol length.