T & P Notices also called as Temporary and Preliminary Notices, are provided in Weekly Notices to Mariners in Section II. These are shown with suffix (T) or (P) after each Notice Number. Temporary Notice may be issued to inform the mariner of any navigation affecting changes which are temporary in nature. Such eg may include - naval exercise, drilling activities, dredging etc.
Preliminary Notices are issued to promulgate navigationally significant data to mariner when -
1. Action or work will shortly be taking place.
2. Information has been received but is too complex to be promulgated by chart updating notice
3. Further confirmation of details is needed. A chart updating Notice will be promulgated or New Edition issued when the details have been confirmed
4. For an ongoing and changeable situation such as a bridge under construction
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