ZCZC SA97 NCC-HAMBURG 130720 UTC APR 26 NAV. WARN. NO. 216 GERMAN BIGHT. OUTER ROUGH. DOGGER TAIL END. GEOPHYSICAL SURVEYS CONDUCTED BY MV 'MIRANDA' CS 'T7AD2' AROUND POSITION 54-480N 003-586E. VESSEL TOWING SURVEY INSTRUMENTS ASTERN. RESTRICTED MANOEVRABILITY DURING OPERATIONS. BERTH OF HPNT NAUTICAL MILES REQUESTED. NNNN