ZCZC IA54 051025 UTC APR SWEDISH NAV WARN 055/26 LOW SEA LEVEL THE SOUND: EARLY MONDAY MORNING BRIEFLY DOWN TO -50 CM BELOW BALTIC SEA CHART DATUM. WESTERN BALTIC: FROM SUNDAY EVENING -50 TO -60 CM CM BELOW BALTIC SEA CHART DATUM. MONDAY AFTERNOON RISING. NNNN