ZCZC FA40 171256 UTC JUL ESTONIAN NAV WARN 111/2026. NORTHERN BALTIC SEA. FOR RESEARCH PURPOSES INSTALLED 4 YELLOW SPECIAL-PURPOSE LIGHT BUOYS FLY2S 35M SW OF SAAREMAA ISLAND BETWEEN POSITIONS: 58-01.4N 021-45.6E 57-59.9N 021-47.9E NAVIGATE WITH CAUTION. NNNN