ZCZC FA53 260601 UTC SEP ESTONIAN NAV WARN 162/26 GULF OF FINLAND. 290600 - 291300 UTC SEP FIRING PRACTICE AREA 4B CENTRED 59-37N 026-22E EXERCISE IN PROGRESS. OTHER VESSELS MUST AVOID ENTRY INTO THE AREA. CANCEL 291300 UTC SEP. NNNN