ZCZC SA20 NCC-HAMBURG 261915 UTC APR 26 NAV. WARN. NO. 242 TSS TERSCHELLING-GERMAN BIGHT.. UNDERWATER OPERATIONS BY MV 'VOS GORGEOUS' CS '2HEN8'. BETWEEN POSITIONS 53-477N 007-035E AND 53-569N 006-569E. RESTRICTED MANOEVRABILITY DURING OPERATIONS 500 M BERTH REQUESTED. NNNN