1. Area with special order of navigation. The time of the area closure is broadcast as PRIP not less than 3 days in advance and is 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 Area with a special regime of the navigation. By the radio is bpoad castedin the shapeof PRIP, not less than 3 days before the area is closed and repeat in every next date by the scheduletill the moment than the area is open for navigation. Then the area is announced as closed for navigation all vessels are strictly prohibited to enter the area and all vessels in this area should leave it in the showen in PRIP time.

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 daily in hydrometeorological messages (METEO). To determine actual depths for the day of navigation it is necessary to add corrections to the depths charted