1.Area with special order of navigation is closed periodically. The time of the area closure is broadcast as PRIP not less than 3 days in advance and repeated each next scheduled time until the area is opened to navigation. When the area is announced closed to navigation all vessels and craft are strictly prohibited to enter it and vessels in the area should leave it by the time indicated in PRIP.
2.Mean Sea Level (1940-1955) is 28.0m lower than the Kronshtadt gauge datum. Information on the sea level is published in the Notices to Mariners. Precised depth corrections are broadcast aily in hydrometeorological messages (METEO). To determine actual depths for the day of navigation it is necessary to add corrections to the depths charted
