Sea Ledger, August 2023

2023-08-01 to 2023-08-31 · archive

issued: 752
warning-days in force: 13,151
in force at month end: 467
sea × type cells: 252

baseline: same month, previous 5 years (2022-08, 2021-08, 2020-08, 2019-08, 2018-08)

By type

type	issued	warning-days	in force at end
Exercises	180	1,365.3	38
Icebergs	105	130.8	6
Incidents	97	876.7	42
Missiles	75	441.1	24
Nav aids	72	4,538.6	151
Surveys	68	2,237.2	84
Cable ops	31	540.7	24
Quakes	31	93.6	2
Derelicts	25	182.8	8
Towing	19	31.6	1
Other	12	500.7	15
Spills	12	200	7
Debris	11	96.4	2
Storms	7	2.4	1
Wrecks	5	1,286.9	42
Containers	1	3	0
Piracy	1	3	0
Mines	0	62	2
Structures	0	124	4
Restricted	0	62	2
War risk	0	31	1
Volcanic	0	248	8
Ordnance	0	93	3

By sea and type · 200 cells, most issued first

cell	issued	warning-days	at end	longest d	vs 5 y
Exercises · North Pacific Oceansurge	60	394.2	11	65	2.1× / 28.2
Icebergs · Southern Ocean	37	48.4	3	31	1.0× / 37.8
Icebergs · South Atlantic Ocean	31	30.9	1	31	1.5× / 20.2
Missiles · Indian Oceansurge	20	100.6	10	37	9.1× / 2.2
Towing · North Pacific Oceansurge	19	31.6	1	31	2.6× / 7.4
Incidents · South China Sea	18	244.2	5	43	0.6× / 28.6
Missiles · North Atlantic Ocean	18	58	3	34	1.5× / 12
Icebergs · Labrador Sea	18	19.1	2	16	0.7× / 26
Incidents · North Atlantic Oceansurge	17	172.7	14	48	2.1× / 8
Icebergs · North Atlantic Oceansurge	14	17.4	0	—	4.7× / 3
Missiles · South Pacific Ocean	13	84.6	3	38	1.6× / 8.2
Nav aids · South Atlantic Oceansurgelong running	12	1,273.2	43	384	2.0× / 6
Surveys · South Atlantic Ocean	12	131.2	8	98	0.7× / 16.2
Exercises · South Atlantic Ocean	12	108.8	2	36	1.1× / 10.4
Exercises · Arabian Sea	12	84	4	35	1.6× / 7.4
Exercises · North Atlantic Ocean	12	52.2	4	29	1.3× / 9.2
Incidents · North Pacific Ocean	11	98.4	5	47	0.6× / 17.8
Exercises · Bay of Bengal	11	75.4	2	34	1.1× / 9.8
Nav aids · North Atlantic Oceanlong running	9	298.4	11	868	1.3× / 6.8
Incidents · South Pacific Ocean	9	47.9	3	25	1.1× / 7.8
Exercises · South Pacific Ocean	9	47.6	0	—	0.9× / 9.6
Cable ops · North Atlantic Ocean	8	122.4	5	83	1.0× / 7.8
Nav aids · North Sea	8	89.9	2	69	1.3× / 6
Missiles · North Pacific Ocean	8	75.6	2	184	1.3× / 6.2
Exercises · Laccadive Seasurge	8	52.3	1	34	3.3× / 2.4
Exercises · Black Sealong running	7	109.5	4	526	0.5× / 14.6
Exercises · Barentsz Seasurge	7	45.9	1	26	3.2× / 2.2
Derelicts · Caribbean Seasurge	7	33.5	2	32	8.8× / 0.8
Nav aids · North Pacific Oceanlong running	6	185.9	6	512	1.4× / 4.2
Exercises · Gulf of Mexicosurge	6	50.9	0	—	4.3× / 1.4
Exercises · Caribbean Seasurge	6	31.9	0	—	2.5× / 2.4
Quakes · South Atlantic Ocean	6	18	0	—	0.7× / 9
Exercises · Celtic Seasurge	6	6.3	0	—	2.1× / 2.8
Nav aids · Gulf of Mexicolong running	5	269.1	8	881	1.9× / 2.6
Surveys · Persian Gulflong running	5	161.8	7	476	0.6× / 8
Surveys · Gulf of Mexicosurge	5	125.4	5	123	8.3× / 0.6
Surveys · Indian Oceansurge	5	90.6	3	188	2.3× / 2.2
Incidents · South Atlantic Ocean	5	63.3	5	36	1.6× / 3.2
Spills · The Coastal Waters of Southeast Alaska and British Columbiasurge	5	54	2	31	4.2× / 1.2
Exercises · Indian Ocean	5	24.5	0	—	1.3× / 4
Exercises · Andaman or Burma Sea	5	21.3	0	—	1.1× / 4.4
Quakes · North Pacific Ocean	5	16	0	—	0.9× / 5.6
Incidents · Laccadive Sea	5	4.1	1	30	1.1× / 4.4
Storms · Gulf of Mexico	5	1.4	0	—	1.0× / 4.8
Nav aids · Caribbean Sealong running	4	870.9	28	926	1.3× / 3
Nav aids · South Pacific Oceanlong running	4	391.4	13	525	1.1× / 3.8
Surveys · Bay of Bengalsurge	4	119.8	3	62	4.0× / 1
Nav aids · Coral Seasurge	4	103.3	5	130	2.0× / 2
Spills · North Pacific Ocean	4	51	2	43	1.0× / 4
Incidents · Caribbean Sea	4	41	3	29	1.8× / 2.2
Exercises · Gulf of Californiasurge	4	33.7	0	—	10× / 0.4
Incidents · Bay of Bengalsurge	4	26.5	0	—	2.9× / 1.4
Incidents · Indian Ocean	4	24.8	0	—	0.7× / 5.8
Quakes · Java Seanew	4	12	0	—	new / 0
Icebergs · Laptev Seasurge	4	12	0	—	6.7× / 0.6
Quakes · South Pacific Ocean	4	12	0	—	0.4× / 10.4
Surveys · Norwegian Sea	3	184.6	7	82	1.7× / 1.8
Surveys · South Pacific Ocean	3	83.3	4	163	1.7× / 1.8
Surveys · Black Seasurge	3	63.2	3	210	3.0× / 1
Surveys · North Pacific Oceansurge	3	29.3	0	—	3.8× / 0.8
Incidents · Mediterranean Sea - Eastern Basin	3	26.3	2	47	1.3× / 2.4
Other · Tasman Seanew	3	12.6	1	12	new / 0
Derelicts · North Pacific Ocean	3	9	0	—	1.4× / 2.2
Cable ops · Strait of Gibraltarsurge	3	8.8	0	—	7.5× / 0.4
Exercises · Bay of Biscaysurge	3	4.5	0	—	3.0× / 1
Derelicts · Indian Ocean	3	4.5	0	—	1.4× / 2.2
Surveys · Kara Sealong running	2	156	3	416	0.8× / 2.6
Wrecks · Arabian Sea	2	129.9	5	326	2.0× / 1
Nav aids · Beaufort Sealong running	2	98.7	4	385	2.5× / 0.8
Surveys · Sea of Okhotsk	2	97.6	3	105	0.9× / 2.2
Nav aids · The Northwestern Passages	2	88.8	3	80	0.7× / 2.8
Cable ops · Persian Gulf	2	86.9	4	162	3.3× / 0.6
Incidents · Gulf of Mexico	2	64.4	1	38	2.0× / 1
Spills · North Atlantic Oceanlong running	2	59	2	406	0.6× / 3.2
Cable ops · North Pacific Ocean	2	57.5	2	41	0.7× / 2.8
Surveys · Arctic Ocean	2	51.4	3	354	2.5× / 0.8
Surveys · North Sea	2	46.2	2	44	0.4× / 5.2
Nav aids · Mediterranean Sea - Eastern Basinlong running	2	45.4	1	820	3.3× / 0.6
Surveys · Chukchi Seanew	2	45.3	2	22	new / 0
Cable ops · Chukchi Seanew	2	33.2	2	16	new / 0
Cable ops · Philippine Sea	2	23.5	1	23	10× / 0.2
Derelicts · North Atlantic Ocean	2	18.3	1	28	0.5× / 3.8
Missiles · Barentsz Sea	2	17.1	0	—	0.5× / 4.4
Derelicts · Arabian Sea	2	16.6	0	—	0.9× / 2.2
Exercises · Japan Sea	2	13.9	1	34	0.9× / 2.2
Cable ops · Hudson Straitnew	2	12.3	0	—	new / 0
Missiles · South Atlantic Ocean	2	11.3	2	5	2.5× / 0.8
Nav aids · English Channel	2	9.6	0	—	0.7× / 2.8
Nav aids · Indian Ocean	2	9.4	1	8	0.8× / 2.6
Incidents · Java Sea	2	7	0	—	1.0× / 2
Surveys · Adriatic Seanew	2	6.2	1	6	new / 0
Debris · North Atlantic Ocean	2	6	0	—	3.3× / 0.6
Debris · North Pacific Ocean	2	6	0	—	5.0× / 0.4
Quakes · Philippine Sea	2	6	0	—	0.9× / 2.2
Cable ops · Beaufort Seanew	2	5.9	1	4	new / 0
Surveys · Philippine Sea	2	5.7	1	8	3.3× / 0.6
Incidents · Bismarck Sea	2	5.4	0	—	1.3× / 1.6
Incidents · Coral Sea	2	4.4	0	—	0.5× / 3.8
Missiles · Coral Seanew	2	2.1	0	—	new / 0
Nav aids · Labrador Seanew	2	2	0	—	new / 0
Derelicts · Philippine Sea	2	1.4	1	1	5.0× / 0.4
Exercises · South China Sea	2	1.4	0	—	1.0× / 2
Other · Hudson Bay	2	1.1	0	—	10× / 0.2
Incidents · Timor Sea	2	1.1	0	—	2.0× / 1
Storms · North Atlantic Ocean	2	1	1	1	0.4× / 5.4
Surveys · North Atlantic Ocean	1	343	11	242	0.1× / 7.6
Nav aids · Arabian Sealong running	1	77.6	3	673	0.8× / 1.2
Wrecks · Coral Sealong running	1	56.7	2	426	2.5× / 0.4
Cable ops · South China Sea	1	56.5	2	85	0.6× / 1.6
Surveys · Bay of Biscay	1	46.5	2	98	1.7× / 0.6
Nav aids · Inner Seas off the West Coast of Scotland	1	40.8	1	48	0.4× / 2.6
Surveys · Caribbean Sea	1	38.8	2	305	0.3× / 3
Spills · Gulf of Mexico	1	36	1	44	0.2× / 6
Cable ops · South Atlantic Ocean	1	35.4	2	69	1.0× / 1
Nav aids · The Coastal Waters of Southeast Alaska and British Columbia	1	34.9	1	172	5.0× / 0.2
Debris · Bay of Biscay	1	34	1	358	2.5× / 0.4
Other · South Pacific Ocean	1	34	1	123	5.0× / 0.2
Derelicts · South Atlantic Ocean	1	33.8	2	166	1.3× / 0.8
Wrecks · Arafura Sea	1	33	1	122	new / 0
Nav aids · Andaman or Burma Sea	1	31	1	115	5.0× / 0.2
Surveys · Mediterranean Sea - Eastern Basin	1	31	1	37	0.3× / 4
Other · Bay of Bengal	1	27	1	26	5.0× / 0.2
Cable ops · Gulf of Suez	1	24.3	1	24	2.5× / 0.4
Surveys · Beaufort Sea	1	22.6	1	22	5.0× / 0.2
Surveys · South China Sea	1	22.6	1	88	0.6× / 1.6
Derelicts · Gulf of Mexico	1	19	1	19	2.5× / 0.4
Other · Arafura Sea	1	16.9	1	16	5.0× / 0.2
Surveys · Coral Sea	1	16.6	1	16	5.0× / 0.2
Incidents · The Northwestern Passages	1	15.4	0	—	1.0× / 1
Exercises · North Sea	1	13.2	0	—	5.0× / 0.2
Incidents · Hudson Bay	1	12.3	1	12	2.5× / 0.4
Nav aids · Gulf of St. Lawrence	1	11	1	10	new / 0
Surveys · English Channel	1	10.9	0	—	2.5× / 0.4
Missiles · Norwegian Sea	1	9.7	0	—	1.0× / 1
Cable ops · Labrador Sea	1	9.2	0	—	new / 0
Missiles · Tasman Sea	1	9	1	8	new / 0
Missiles · Philippine Sea	1	8.8	0	—	new / 0
Surveys · East Siberian Sea	1	8.5	1	8	new / 0
Nav aids · Arafura Sea	1	7.7	1	7	2.5× / 0.4
Missiles · Arctic Ocean	1	7	0	—	0.7× / 1.4
Missiles · Kara Sea	1	6.6	1	6	2.5× / 0.4
Other · Gulf of Alaska	1	6.3	0	—	2.5× / 0.4
Missiles · Japan Sea	1	6.1	1	6	1.3× / 0.8
Missiles · Bay of Bengal	1	5.9	0	—	5.0× / 0.2
Cable ops · Singapore Strait	1	5.8	1	5	new / 0
Exercises · Bering Sea	1	5.6	1	5	2.5× / 0.4
Missiles · Black Sea	1	5.5	0	—	0.2× / 4.2
Debris · Mediterranean Sea - Western Basin	1	5.5	0	—	new / 0
Wrecks · Mediterranean Sea - Western Basin	1	5.4	0	—	new / 0
Derelicts · Coral Sea	1	5.3	0	—	2.5× / 0.4
Cable ops · Laccadive Sea	1	4.5	0	—	new / 0
Cable ops · Mediterranean Sea - Western Basin	1	4.5	1	4	5.0× / 0.2
Derelicts · Halmahera Sea	1	4.4	0	—	new / 0
Debris · Tasman Sea	1	4.2	0	—	2.5× / 0.4
Derelicts · Arafura Sea	1	3	0	—	new / 0
Quakes · Bering Sea	1	3	0	—	new / 0
Debris · Caribbean Sea	1	3	0	—	5.0× / 0.2
Containers · Celtic Sea	1	3	0	—	new / 0
Debris · Celtic Sea	1	3	0	—	5.0× / 0.2
Quakes · Coral Sea	1	3	0	—	0.4× / 2.6
Quakes · Flores Sea	1	3	0	—	5.0× / 0.2
Quakes · Gulf of Alaska	1	3	0	—	2.5× / 0.4
Quakes · Indian Ocean	1	3	0	—	0.3× / 3
Icebergs · Kara Sea	1	3	0	—	0.6× / 1.6
Quakes · Molukka Sea	1	3	0	—	2.5× / 0.4
Debris · Persian Gulf	1	3	0	—	new / 0
Quakes · Red Sea	1	3	0	—	new / 0
Quakes · Solomon Sea	1	3	0	—	0.8× / 1.2
Piracy · South China Sea	1	3	0	—	new / 0
Derelicts · South Pacific Ocean	1	3	0	—	0.6× / 1.8
Nav aids · Tasman Sea	1	3	0	—	1.0× / 1
Other · Irish Sea and St. George's Channel	1	2.9	0	—	new / 0
Quakes · Banda Sea	1	2.8	1	2	1.7× / 0.6
Quakes · Caribbean Sea	1	2.8	1	2	0.6× / 1.8
Incidents · Solomon Sea	1	2.8	0	—	1.0× / 1
Other · North Sea	1	2.6	0	—	2.5× / 0.4
Incidents · Mediterranean Sea - Western Basin	1	2.3	1	2	1.3× / 0.8
Surveys · Timor Sea	1	2.3	0	—	new / 0
Exercises · Norwegian Sea	1	2.2	1	2	1.3× / 0.8
Missiles · Laccadive Sea	1	1.8	0	—	0.8× / 1.2
Incidents · Gulf of Alaska	1	1.6	1	1	new / 0
Cable ops · Arabian Sea	1	1.5	1	1	5.0× / 0.2
Nav aids · Davis Strait	1	0.8	0	—	0.4× / 2.4
Other · North Pacific Ocean	1	0.8	0	—	0.1× / 7.6
Debris · Barentsz Sea	1	0.7	0	—	2.5× / 0.4
Missiles · South China Sea	1	0.4	0	—	new / 0
Surveys · Arabian Sea	1	0.3	1	0	0.7× / 1.4
Incidents · Baffin Bay	1	0.2	0	—	5.0× / 0.2
Incidents · Tasman Sea	1	0	0	—	1.3× / 0.8
Volcanic · Philippine Sealong running	0	248	8	986	0.0× / 1.2
Wrecks · South Atlantic Oceanlong running	0	186	6	461	0.0× / 0.6
Exercises · Aegean Sea	0	155	5	241	0.0× / 0.4
Surveys · The Northwestern Passageslong running	0	155	5	377	0.0× / 1.4
Wrecks · The Northwestern Passageslong running	0	155	5	728	0.0× / 1.2
Nav aids · Laccadive Sealong running	0	146	4	443	0.0× / 0.6
Wrecks · Caribbean Sea	0	127.7	4	344	0.0× / 0.4
Ordnance · Bay of Biscay	0	93	3	73	— / 0
Other · Caribbean Sealong running	0	93	3	672	0.0× / 0.6
Wrecks · Hudson Bay	0	93	3	307	— / 0
Wrecks · Laccadive Sea	0	93	3	195	0.0× / 0.2

Cite: seahazards.com Sea Ledger, 2023-08, 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.