Sea Ledger, September 2026

2026-09-01 to 2026-09-30 · month in progress · live

issued: 75
warning-days in force: 1,222
in force at month end: 441
sea × type cells: 163

baseline: same month, previous 5 years (2023-09, 2022-09, 2021-09)

By type

type	issued	warning-days	in force at end
Exercises	23	127.4	46
Missiles	10	29.3	9
Icebergs	10	10.4	2
Surveys	9	189.4	68
Storms	6	3.9	6
Quakes	5	9.6	5
Other	3	53.7	19
Nav aids	3	494.7	178
Wrecks	2	105.6	38
Cable ops	2	91.7	33
Derelicts	1	11.8	4
Debris	1	6.4	2
Mines	0	16.6	6
Spills	0	24.2	8
Restricted	0	8.3	3
Structures	0	2.8	1
War risk	0	5.5	2
Volcanic	0	30.3	11

By sea and type · 163 cells, most issued first

cell	issued	warning-days	at end	longest d	vs 5 y
Exercises · North Pacific Ocean	8	40.7	14	41	0.2× / 32.67
Missiles · South Pacific Ocean	5	9.7	3	10	0.4× / 12
Surveys · South Atlantic Ocean	4	14.3	5	279	0.2× / 25.67
Exercises · Philippine Sea	4	11.9	5	7	1.2× / 3.33
Storms · North Pacific Oceannew	4	0.5	4	0	new / 0
Surveys · Indian Ocean	3	28.7	11	158	1.0× / 3
Exercises · Bay of Bengal	3	8.6	3	34	0.2× / 15
Exercises · North Atlantic Ocean	3	6.6	3	17	0.3× / 9
Icebergs · South Atlantic Ocean	3	1	0	—	0.2× / 19.33
Other · Persian Gulflong running	2	11.1	4	598	6.1× / 0.33
Icebergs · Labrador Sea	2	4.8	1	6	0.1× / 27
Icebergs · Southern Ocean	2	3.5	1	65	0.1× / 36
Quakes · North Pacific Ocean	2	1.5	2	1	0.3× / 8
Icebergs · Laptev Sea	2	1	0	—	1.2× / 1.67
Nav aids · North Atlantic Oceanlong running	1	49.9	18	1,710	0.1× / 9
Nav aids · South Atlantic Ocean	1	41.2	14	182	0.1× / 7.67
Nav aids · North Pacific Oceanlong running	1	27.9	10	1,602	0.2× / 5
Wrecks · Kara Sea	1	8.3	3	8	3.0× / 0.33
Exercises · Laccadive Sea	1	5.6	2	34	0.2× / 5
Missiles · North Atlantic Ocean	1	3.6	1	9	0.1× / 15.33
Cable ops · Indian Ocean	1	3.1	1	21	1.0× / 1
Surveys · North Sea	1	2.9	1	17	0.6× / 1.67
Storms · Philippine Sea	1	2.9	2	55	new / 0
Other · Black Sealong running	1	2.8	1	884	new / 0
Exercises · Indian Ocean	1	2.8	1	6	0.4× / 2.33
Surveys · Caribbean Sea	1	2.6	0	—	0.3× / 3.33
Quakes · South Pacific Ocean	1	2.6	1	4	0.1× / 9.33
Quakes · Halmahera Sea	1	2.4	1	2	new / 0
Debris · Black Sea	1	0.9	0	—	new / 0
Missiles · Arctic Ocean	1	0.8	0	—	1.5× / 0.67
Exercises · Barentsz Sea	1	0.8	0	—	0.3× / 3
Quakes · South Atlantic Ocean	1	0.8	1	0	0.3× / 3.67
Derelicts · North Pacific Ocean	1	0.6	0	—	0.8× / 1.33
Exercises · Tasman Sea	1	0.6	0	—	0.4× / 2.33
Wrecks · Davis Strait	1	0.5	0	—	new / 0
Missiles · Greenland Sea	1	0.5	0	—	new / 0
Storms · South China Sea	1	0.5	0	—	new / 0
Missiles · Barentsz Sea	1	0.2	0	—	0.1× / 7.67
Cable ops · Arabian Sea	1	0.1	0	—	0.6× / 1.67
Missiles · Bay of Bengal	1	0.1	0	—	1.0× / 1
Icebergs · Kara Sea	1	0.1	0	—	3.0× / 0.33
Exercises · Red Sea	1	0	0	—	1.5× / 0.67
Nav aids · Caribbean Sealong running	0	138	50	2,024	0.0× / 2
Surveys · North Atlantic Oceanlong running	0	46.9	17	973	0.0× / 6
Nav aids · South Pacific Oceanlong running	0	33.1	12	938	0.0× / 5.33
Nav aids · North Sea	0	30.4	11	53	0.0× / 5.33
Volcanic · Philippine Sealong running	0	24.8	9	2,085	0.0× / 0.33
Surveys · Black Sealong running	0	19.3	7	612	0.0× / 0.33
Nav aids · Gulf of Mexicolong running	0	19.3	7	1,980	0.0× / 1
Cable ops · North Atlantic Ocean	0	19.3	7	243	0.0× / 7.67
Exercises · Arabian Sea	0	16.6	6	44	0.0× / 13.67
Nav aids · Persian Gulf	0	16.6	6	333	0.0× / 1
Nav aids · Beaufort Sealong running	0	13.8	5	1,484	0.0× / 1
Mines · Black Sealong running	0	13.8	5	1,651	0.0× / 0.33
Wrecks · Persian Gulflong running	0	13.8	5	952	— / 0
Wrecks · South China Sealong running	0	13.8	5	2,737	— / 0
Nav aids · Arabian Sea	0	11	4	134	0.0× / 1.33
Wrecks · Caribbean Sealong running	0	11	4	786	0.0× / 0.33
Wrecks · North Atlantic Ocean	0	11	4	176	— / 0
Cable ops · North Pacific Oceanlong running	0	11	4	675	0.0× / 1.67
Missiles · North Pacific Oceanlong running	0	11	4	1,282	0.0× / 6
Surveys · Persian Gulflong running	0	11	4	467	0.0× / 4.33
Nav aids · Philippine Sealong running	0	11	4	658	— / 0
Surveys · Timor Sea	0	11	4	98	— / 0
Spills · North Pacific Ocean	0	9.3	3	15	0.0× / 2.33
Wrecks · Arabian Sealong running	0	8.3	3	856	0.0× / 0.33
Nav aids · Bering Sealong running	0	8.3	3	450	0.0× / 0.33
Surveys · Bering Sealong running	0	8.3	3	416	— / 0
Nav aids · Coral Sea	0	8.3	3	7	0.0× / 3
Spills · Gulf of Mexico	0	8.3	3	10	0.0× / 2
Other · Indian Oceanlong running	0	8.3	3	947	— / 0
Surveys · Sea of Okhotsk	0	8.3	3	133	0.0× / 1.33
Wrecks · South Atlantic Oceanlong running	0	8.3	3	460	0.0× / 0.67
Cable ops · South China Sea	0	8.3	3	44	0.0× / 0.33
Wrecks · The Northwestern Passageslong running	0	8.3	3	368	0.0× / 2.67
Exercises · Aegean Sea	0	5.5	2	212	— / 0
Nav aids · Bay of Bengal	0	5.5	2	132	— / 0
Cable ops · Black Sea	0	5.5	2	331	— / 0
War risk · Black Sealong running	0	5.5	2	1,625	— / 0
Surveys · Coral Sea	0	5.5	2	36	0.0× / 0.33
Nav aids · English Channel	0	5.5	2	38	0.0× / 2.67
Nav aids · Great Australian Bight	0	5.5	2	66	0.0× / 0.33
Nav aids · Gulf of Alaskalong running	0	5.5	2	485	0.0× / 1.33
Surveys · Gulf of Guinea	0	5.5	2	25	— / 0
Wrecks · Gulf of Guinea	0	5.5	2	105	— / 0
Nav aids · Gulf of Omanlong running	0	5.5	2	879	— / 0
Nav aids · Indian Ocean	0	5.5	2	20	0.0× / 1.33
Nav aids · Mediterranean Sea - Eastern Basinlong running	0	5.5	2	665	— / 0
Exercises · Mediterranean Sea - Western Basin	0	5.5	2	70	0.0× / 1.33
Other · North Atlantic Ocean	0	5.5	2	164	0.0× / 2.67
Debris · North Pacific Oceanlong running	0	5.5	2	435	0.0× / 1.33
Volcanic · North Pacific Ocean	0	5.5	2	49	— / 0
Cable ops · North Sea	0	5.5	2	31	0.0× / 1.33
Surveys · Norwegian Sea	0	5.5	2	62	— / 0
Restricted · Persian Gulflong running	0	5.5	2	605	— / 0
Nav aids · Sea of Okhotsklong running	0	5.5	2	582	— / 0
Nav aids · Singapore Strait	0	5.5	2	74	— / 0
Cable ops · South Atlantic Ocean	0	5.5	2	63	0.0× / 0.67
Exercises · South Atlantic Ocean	0	5.5	2	36	0.0× / 17
Other · South Atlantic Ocean	0	5.5	2	38	0.0× / 1.33
Exercises · South China Sea	0	5.5	2	10	— / 0
Cable ops · Sulu Sealong running	0	5.5	2	899	— / 0
Cable ops · Tasman Sea	0	5.5	2	66	— / 0
Missiles · Aegean Sea	0	2.8	1	212	— / 0
Exercises · Andaman or Burma Sea	0	2.8	1	6	0.0× / 3.67
Nav aids · Andaman or Burma Sea	0	2.8	1	27	0.0× / 1
Derelicts · Arabian Sea	0	2.8	1	44	0.0× / 0.67
Derelicts · Arafura Sea	0	2.8	1	31	0.0× / 1
Surveys · Arctic Oceanlong running	0	2.8	1	625	0.0× / 1
Nav aids · Bass Strait	0	2.8	1	59	0.0× / 0.33
Other · Bass Strait	0	2.8	1	17	— / 0
Surveys · Bass Strait	0	2.8	1	14	— / 0
Cable ops · Bering Sea	0	2.8	1	46	— / 0
Exercises · Black Sealong running	0	2.8	1	1,625	0.0× / 5
Nav aids · Black Sealong running	0	2.8	1	717	— / 0
Exercises · Caribbean Sealong running	0	2.8	1	527	0.0× / 5
Other · Caribbean Sealong running	0	2.8	1	1,282	0.0× / 0.33
Spills · Caribbean Sealong running	0	2.8	1	638	0.0× / 0.33
Other · Celtic Sea	0	2.8	1	44	— / 0
Other · Davis Strait	0	2.8	1	285	— / 0
Wrecks · Eastern China Sealong running	0	2.8	1	1,133	— / 0
Cable ops · Great Australian Bight	0	2.8	1	96	— / 0
Other · Great Australian Bight	0	2.8	1	96	— / 0
Surveys · Great Australian Bight	0	2.8	1	17	— / 0
Spills · Gulf of Alaska	0	2.8	1	10	— / 0
Nav aids · Gulf of Californialong running	0	2.8	1	1,601	— / 0
Nav aids · Gulf of Guinea	0	2.8	1	75	— / 0
Surveys · Gulf of Mexico	0	2.8	1	80	0.0× / 1.67
Wrecks · Gulf of Mexico	0	2.8	1	226	— / 0
Derelicts · Gulf of Omanlong running	0	2.8	1	441	— / 0
Nav aids · Hudson Bay	0	2.8	1	52	0.0× / 1
Nav aids · Hudson Strait	0	2.8	1	51	— / 0
Wrecks · Hudson Strait	0	2.8	1	307	— / 0
Nav aids · Inner Seas off the West Coast of Scotland	0	2.8	1	26	0.0× / 3.33
Nav aids · Irish Sea and St. George's Channel	0	2.8	1	30	0.0× / 1.33
Exercises · Japan Sea	0	2.8	1	38	0.0× / 3.67
Wrecks · Java Sea	0	2.8	1	10	— / 0
Other · Kara Sea	0	2.8	1	39	— / 0
Surveys · Kara Sea	0	2.8	1	35	— / 0
Nav aids · Laccadive Sea	0	2.8	1	27	0.0× / 0.67
Wrecks · Laccadive Sea	0	2.8	1	7	— / 0
Cable ops · Laptev Sea	0	2.8	1	29	— / 0
Cable ops · Makassar Strait	0	2.8	1	219	— / 0
Surveys · Makassar Strait	0	2.8	1	219	— / 0
Restricted · Mozambique Channel	0	2.8	1	234	— / 0
Structures · North Pacific Ocean	0	2.8	1	308	— / 0
Wrecks · North Pacific Oceanlong running	0	2.8	1	413	— / 0
Other · North Sea	0	2.8	1	30	0.0× / 1.67
Cable ops · Norwegian Sea	0	2.8	1	62	0.0× / 0.33
Cable ops · Persian Gulf	0	2.8	1	25	0.0× / 1
Mines · Persian Gulf	0	2.8	1	76	— / 0
Derelicts · Red Sealong running	0	2.8	1	623	— / 0
Nav aids · South China Sealong running	0	2.8	1	1,004	0.0× / 0.33
Surveys · South China Sea	0	2.8	1	28	0.0× / 0.33
Cable ops · South Pacific Ocean	0	2.8	1	37	— / 0
Nav aids · The Coastal Waters of Southeast Alaska and British Columbia	0	2.8	1	78	— / 0
Cable ops · Timor Sea	0	2.8	1	29	— / 0
Nav aids · Timor Sea	0	2.8	1	98	— / 0
Quakes · Flores Sea	0	2.3	0	—	— / 0
Spills · North Atlantic Ocean	0	1	0	—	0.0× / 1.67
Other · Coral Sea	0	0.9	0	—	— / 0
Missiles · White Sea	0	0.6	0	—	— / 0
Other · Adriatic Sea	0	0	0	—	— / 0

Cite: seahazards.com Sea Ledger, 2026-09, 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.