Sea Ledger, September 1999
1999-09-01 to 1999-09-30 · archive
- issued
- 319
- warning-days in force
- 5,867
- in force at month end
- 196
- sea × type cells
- 168
baseline: same month, previous 5 years — not available for this month (needs three fully collected reference months)
By type
| type | issued | warning-days | in force at end |
|---|---|---|---|
| Nav aids | 60 | 1,766.2 | 55 |
| Exercises | 47 | 265.8 | 13 |
| Incidents | 43 | 462.1 | 15 |
| Quakes | 33 | 94.3 | 3 |
| Surveys | 32 | 269 | 7 |
| Cable ops | 28 | 476.5 | 19 |
| Icebergs | 22 | 134.8 | 5 |
| Missiles | 15 | 90.9 | 2 |
| Wrecks | 11 | 514.2 | 18 |
| Other | 6 | 471.7 | 14 |
| Derelicts | 6 | 49.1 | 2 |
| Spills | 6 | 70 | 4 |
| Ordnance | 4 | 857.3 | 29 |
| Containers | 4 | 27.5 | 0 |
| Mines | 1 | 70.5 | 2 |
| Debris | 1 | 7.2 | 0 |
| War risk | 0 | 30 | 1 |
| Structures | 0 | 120 | 4 |
| Restricted | 0 | 30 | 1 |
| Volcanic | 0 | 60 | 2 |
By sea and type · 168 cells, most issued first
Cite: seahazards.com Sea Ledger, 1999-09, retrieved 2026-09-03
Not for navigation. Warning-days = days each warning was in force within the month, summed. Only warnings we display are counted; the ratio compares warnings issued with the mean of the reference months.