Vertical Datum: LAT The UC21 was sunk in mine nets, 1917. 17-OCT-1946 Least echosounder sounding 62ft e7934 with curator position 51 30 00N 001 34 42E 086.5Deg 7.92Min from Tongue Sand. 25-APR-1956 Oropesa sweep, clear at 53ft least depth by echo sounder 58ft in general depth 71ft. Position 51 30 06N 001 34 43E, small wreck, no swirl. 09-DEC-1970 Position 51 30 04N 001 34 47E, echosounder 17.4m (57Ft) in 21m (69ft) scour 21.8m (72Ft), flat seabed. Only a small piece of wreckage 400ft SE of charted position. Area around charted position closely sounded. Nothing further found. Contacts to SE of charted position. 10-NOV-1976 Obstruction shown in position 51 30 04N 001 34 47E Kingfisher chart KE 151-2, July 1968 Edition. 08-NOV-1983 In 51 30 04N 001 34 46E least echosounder depth 18.4 in general depth 21.5m, Scour depth 1m. Side scan sonar height 2.5m. Lying NE/SW. 15-FEB-1990 Located during area search. Not examined closely.

<1> Hydrographic Office wreck index, Extracted 20-JAN-1993, Page Nos. N/a (Bibliographic reference). SKE6339.

<2> Cotswold Archaeology, 2014, NHPP 3A1: Unknown Marine Assets & Landscapes, Strategic Assessment of Submarines, in English Waters, Project Report (Unpublished document). SKE53522.