ZCZC FA27 100900 UTC SEP LATVIAN NAV WARN 025/26 BALTIC SEA GULF OF RIGA FIRING EXERCISE IN PROGRESS SEP 14 FROM 0500 1700 UTC IN M1 AREA CENTERED IN PSN 57-26.00N 023-45.00E AREA CLOSED FOR NAVIGATION DURING EXERCISE WIDE BERTH REQUESTED INFORMATION ON RESTRICTIONS ON VHF CH 16 CANCEL THIS MSG ON 141800 UTC SEP NNNN