Sea Ledger, March 2023

2023-03-01 to 2023-03-31 · archive

issued: 767
warning-days in force: 14,397
in force at month end: 467
sea × type cells: 237

baseline: same month, previous 5 years (2022-03, 2021-03, 2020-03, 2019-03, 2018-03)

By type

type	issued	warning-days	in force at end
Exercises	187	1,444.6	53
Incidents	118	1,150	35
Icebergs	93	101	3
Nav aids	75	4,556.5	142
Surveys	72	2,795.7	96
Missiles	61	374.3	10
Quakes	35	96.8	2
Cable ops	29	542.8	20
Derelicts	24	201.5	9
Other	15	827.2	24
Spills	15	221	6
Debris	13	130.6	4
Wrecks	10	1,308.6	43
Towing	7	13.6	1
Piracy	4	12	0
Restricted	3	42.1	2
Mines	2	65.3	2
Ordnance	2	39.7	1
Structures	1	160.2	4
Containers	1	34	1
Volcanic	0	248	8
War risk	0	31	1

By sea and type · 200 cells, most issued first

cell	issued	warning-days	at end	longest d	vs 5 y
Exercises · North Pacific Ocean	49	304.9	19	63	1.8× / 27.2
Icebergs · Southern Ocean	43	42.5	0	—	1.3× / 33.2
Icebergs · Labrador Sea	31	36.2	2	32	1.4× / 21.8
Missiles · North Atlantic Oceansurge	26	88.5	0	—	3.1× / 8.4
Incidents · South China Sea	23	133.6	4	48	0.9× / 25.8
Surveys · Arabian Seasurge	20	381.9	13	72	2.5× / 8
Exercises · Arabian Sea	18	103.3	2	35	1.7× / 10.6
Icebergs · South Atlantic Ocean	17	16.3	1	29	0.7× / 23.6
Nav aids · South Atlantic Ocean	15	1,263.4	43	231	1.5× / 10
Exercises · South Pacific Ocean	15	77.9	0	—	1.5× / 10.2
Exercises · Celtic Seasurge	15	22.3	0	—	4.0× / 3.8
Quakes · South Pacific Ocean	14	35.6	1	32	0.7× / 20
Incidents · North Atlantic Ocean	13	244.3	9	147	1.4× / 9.6
Exercises · Bay of Bengal	11	104.6	0	—	1.1× / 9.8
Incidents · South Pacific Ocean	11	97.1	5	35	1.5× / 7.2
Incidents · North Pacific Ocean	11	64.6	2	44	1.1× / 10
Surveys · North Atlantic Oceansurge	10	649.7	24	283	2.4× / 4.2
Surveys · South Atlantic Ocean	10	258.6	7	207	0.5× / 20
Exercises · North Atlantic Ocean	10	116.5	1	104	1.8× / 5.6
Incidents · Indian Ocean	10	65.8	3	33	1.7× / 5.8
Missiles · Indian Oceansurge	10	34.7	2	35	2.2× / 4.6
Exercises · Gulf of Mexicosurge	9	37.5	9	4	4.1× / 2.2
Nav aids · North Pacific Oceansurgelong running	8	229.1	4	728	2.4× / 3.4
Cable ops · Arabian Seasurge	8	146.1	4	44	3.3× / 2.4
Exercises · Black Sealong running	8	100.2	4	373	0.6× / 14.4
Spills · Gulf of Mexicosurge	8	80	4	39	3.6× / 2.2
Missiles · Barentsz Seasurge	8	60.6	3	21	2.1× / 3.8
Exercises · Bay of Biscaysurge	8	9	0	—	3.1× / 2.6
Incidents · Coral Seasurge	8	7.3	2	30	2.1× / 3.8
Incidents · Gulf of Mexicosurge	7	141.9	2	89	5.8× / 1.2
Exercises · Laccadive Seasurge	7	60.6	0	—	3.9× / 1.8
Towing · North Pacific Ocean	7	13.6	1	13	1.4× / 5.2
Surveys · Indian Oceansurge	6	173	6	349	2.7× / 2.2
Nav aids · North Sea	6	155.1	5	295	0.5× / 11.6
Derelicts · South Pacific Oceansurge	6	48	2	179	4.3× / 1.4
Nav aids · Coral Sea	6	36.1	3	27	0.8× / 7.4
Exercises · Caribbean Sea	6	25	3	30	1.5× / 4
Quakes · North Pacific Ocean	6	18	0	—	1.1× / 5.2
Debris · North Pacific Oceansurge	6	17.6	1	28	15× / 0.4
Derelicts · Caribbean Seasurge	6	12	2	32	2.3× / 2.6
Wrecks · Persian Gulfsurgelong running	5	166.3	6	758	8.3× / 0.6
Surveys · Bay of Bengalsurge	5	165.9	6	119	2.5× / 2
Exercises · South Atlantic Ocean	5	76.8	2	274	0.6× / 9
Nav aids · Arafura Seasurge	5	49.6	2	268	13× / 0.4
Incidents · Bay of Bengalsurge	5	31.3	0	—	6.3× / 0.8
Nav aids · Inner Seas off the West Coast of Scotland	5	30.3	0	—	1.3× / 3.8
Derelicts · North Atlantic Ocean	5	25.1	1	25	1.9× / 2.6
Exercises · Andaman or Burma Sea	5	24	0	—	1.3× / 4
Cable ops · North Pacific Oceansurge	5	23.5	1	23	2.5× / 2
Nav aids · South Pacific Oceanlong running	4	612	19	619	0.9× / 4.4
Surveys · Persian Gulflong running	4	305.5	11	802	0.7× / 5.8
Nav aids · North Atlantic Oceanlong running	4	267.2	9	715	0.8× / 4.8
Nav aids · Celtic Seasurge	4	68	1	224	3.3× / 1.2
Incidents · South Atlantic Ocean	4	50.2	2	20	0.7× / 6
Missiles · South Pacific Ocean	4	47	0	—	1.3× / 3.2
Incidents · Bismarck Seasurge	4	27.3	0	—	3.3× / 1.2
Surveys · South Pacific Oceansurge	4	22.9	2	14	4.0× / 1
Exercises · Gulf of Californiasurge	4	16.6	4	4	5.0× / 0.8
Quakes · Bismarck Seasurge	4	12	0	—	20× / 0.2
Nav aids · Caribbean Sealong running	3	734.9	24	773	1.5× / 2
Other · Caribbean Seasurgelong running	3	89.5	3	519	7.5× / 0.4
Incidents · Arabian Sea	3	80.2	2	66	0.6× / 5.2
Surveys · Caribbean Sea	3	62	2	152	1.9× / 1.6
Cable ops · Mozambique Channelnew	3	56.2	3	34	new / 0
Incidents · Caribbean Sea	3	52.7	0	—	1.1× / 2.8
Missiles · North Pacific Ocean	3	40.8	1	31	0.7× / 4.4
Nav aids · Great Australian Bightsurge	3	31.8	1	22	3.8× / 0.8
Exercises · Barentsz Seasurge	3	29.2	1	40	2.1× / 1.4
Quakes · Coral Sea	3	9	0	—	1.9× / 1.6
Debris · Indian Ocean	3	7	0	—	1.5× / 2
Cable ops · Persian Gulflong running	2	135.5	6	596	5.0× / 0.4
Wrecks · Caribbean Sealong running	2	90.8	3	524	2.5× / 0.8
Wrecks · Laccadive Sea	2	86.4	4	106	10× / 0.2
Spills · North Atlantic Ocean	2	58	2	253	0.5× / 4
Surveys · Black Sea	2	53.1	3	57	1.1× / 1.8
Nav aids · Irish Sea and St. George's Channel	2	47.8	1	274	1.4× / 1.4
Incidents · Mediterranean Sea - Eastern Basin	2	44.8	0	—	0.3× / 6.8
Missiles · South Atlantic Ocean	2	38.4	3	37	1.7× / 1.2
Spills · North Pacific Ocean	2	34	0	—	0.8× / 2.4
Exercises · Norwegian Sea	2	32	0	—	5.0× / 0.4
Exercises · Japan Sea	2	30.2	1	36	0.9× / 2.2
Other · South China Sea	2	20.1	0	—	3.3× / 0.6
Incidents · Philippine Sea	2	19.4	0	—	0.6× / 3.6
Surveys · Balearic (Iberian Sea)new	2	17.7	1	22	new / 0
Surveys · Bay of Biscay	2	17.2	0	—	2.5× / 0.8
Missiles · Japan Sea	2	14	0	—	0.5× / 4
Derelicts · South Atlantic Ocean	2	13.9	1	13	0.8× / 2.6
Cable ops · Bay of Bengal	2	11.7	0	—	5.0× / 0.4
Cable ops · South China Sea	2	11.5	1	11	2.0× / 1
Missiles · Norwegian Sea	2	9.4	0	—	10× / 0.2
Exercises · Tyrrhenian Seanew	2	9	0	—	new / 0
Restricted · North Atlantic Oceannew	2	8.7	1	8	new / 0
Ordnance · North Pacific Ocean	2	8.7	0	—	3.3× / 0.6
Icebergs · North Atlantic Ocean	2	6	0	—	0.2× / 10
Quakes · Philippine Sea	2	6	0	—	1.1× / 1.8
Quakes · Solomon Sea	2	6	0	—	0.7× / 2.8
Piracy · South Atlantic Oceannew	2	6	0	—	new / 0
Exercises · Coral Sea	2	4.1	0	—	2.0× / 1
Mines · Persian Gulfnew	2	3.3	0	—	new / 0
Other · Gulf of St. Lawrencenew	2	0.6	0	—	new / 0
Nav aids · Indian Ocean	2	0.3	0	—	1.7× / 1.2
Incidents · Bass Straitnew	2	0.1	0	—	new / 0
Nav aids · Laccadive Sea	1	144.5	4	290	0.8× / 1.2
Nav aids · Arabian Sealong running	1	121.2	3	520	1.7× / 0.6
Other · Persian Gulf	1	117.3	4	239	2.5× / 0.4
Other · North Atlantic Ocean	1	116.9	4	193	0.1× / 7.4
Surveys · Laccadive Sealong running	1	88.4	2	412	new / 0
Structures · South Atlantic Ocean	1	70.6	2	245	5.0× / 0.2
Wrecks · North Sealong running	1	62.7	2	475	1.7× / 0.6
Cable ops · Laccadive Sea	1	37.8	1	37	new / 0
Cable ops · Red Sea	1	35	1	37	new / 0
Debris · South Pacific Ocean	1	35	1	64	1.3× / 0.8
Derelicts · Bay of Bengal	1	32.6	1	287	2.5× / 0.4
Other · Southern Oceanlong running	1	32	1	413	new / 0
Other · Black Sea	1	30.5	1	132	5.0× / 0.2
Incidents · Mozambique Channel	1	26.8	1	47	2.5× / 0.4
Cable ops · Indian Ocean	1	25.4	1	41	2.5× / 0.4
Cable ops · Gulf of Guinea	1	22	1	22	2.5× / 0.4
Spills · The Coastal Waters of Southeast Alaska and British Columbia	1	21	0	—	0.8× / 1.2
Exercises · Tasman Sea	1	19.9	1	19	new / 0
Other · Mediterranean Sea - Eastern Basin	1	19.1	0	—	2.5× / 0.4
Nav aids · The Coastal Waters of Southeast Alaska and British Columbia	1	19.1	1	19	1.0× / 1
Incidents · Bering Sea	1	17.1	0	—	new / 0
Cable ops · North Atlantic Ocean	1	16.9	0	—	0.2× / 5.2
Incidents · Laccadive Sea	1	15.1	0	—	0.6× / 1.6
Spills · Beaufort Sea	1	14	0	—	new / 0
Spills · Philippine Sea	1	14	0	—	new / 0
Surveys · Ligurian Sea	1	13.4	0	—	5.0× / 0.2
Nav aids · English Channel	1	12.2	0	—	0.5× / 2.2
Cable ops · Gulf of Mexico	1	9.7	0	—	5.0× / 0.2
Missiles · Philippine Sea	1	6.6	0	—	new / 0
Incidents · Tasman Sea	1	6.6	1	6	1.3× / 0.8
Exercises · Mediterranean Sea - Eastern Basin	1	5.3	0	—	0.1× / 20.2
Exercises · Persian Gulf	1	4.7	0	—	5.0× / 0.2
Exercises · Adriatic Sea	1	4.2	0	—	new / 0
Nav aids · South China Sea	1	4.1	0	—	5.0× / 0.2
Incidents · Solomon Sea	1	3.9	0	—	new / 0
Surveys · Mediterranean Sea - Western Basin	1	3.5	0	—	0.8× / 1.2
Debris · Coral Sea	1	3	0	—	new / 0
Derelicts · Gulf of Mexico	1	3	0	—	2.5× / 0.4
Derelicts · Indian Ocean	1	3	0	—	0.7× / 1.4
Other · Indian Ocean	1	3	0	—	1.0× / 1
Containers · North Atlantic Ocean	1	3	0	—	0.8× / 1.2
Quakes · North Atlantic Ocean	1	3	0	—	0.6× / 1.6
Debris · Persian Gulf	1	3	0	—	5.0× / 0.2
Piracy · Red Sea	1	3	0	—	new / 0
Quakes · South Atlantic Ocean	1	3	0	—	0.6× / 1.8
Quakes · South China Sea	1	3	0	—	2.5× / 0.4
Piracy · South Pacific Ocean	1	3	0	—	5.0× / 0.2
Debris · Timor Sea	1	3	0	—	1.7× / 0.6
Derelicts · Arafura Sea	1	2.7	0	—	5.0× / 0.2
Other · North Pacific Ocean	1	2.7	0	—	0.8× / 1.2
Cable ops · Malacca Strait	1	2.5	1	2	new / 0
Restricted · Mozambique Channel	1	2.4	0	—	new / 0
Incidents · Adriatic Sea	1	1.9	1	1	5.0× / 0.2
Surveys · Philippine Sea	1	1.9	1	1	1.7× / 0.6
Missiles · Laccadive Sea	1	1.8	0	—	1.0× / 1
Nav aids · Gulf of St. Lawrence	1	1.7	0	—	new / 0
Derelicts · Banda Sea	1	1.5	1	1	new / 0
Exercises · Indian Ocean	1	1.5	0	—	0.7× / 1.4
Exercises · Philippine Sea	1	1.2	0	—	0.1× / 8.8
Nav aids · Bass Strait	1	1.1	0	—	1.3× / 0.8
Missiles · South China Sea	1	0.8	0	—	new / 0
Missiles · Gulf of Mexico	1	0.7	0	—	new / 0
Incidents · Java Sea	1	0.6	0	—	0.5× / 2
Other · South Pacific Ocean	1	0.4	0	—	0.4× / 2.4
Incidents · Great Australian Bight	1	0.3	0	—	5.0× / 0.2
Incidents · Red Sea	1	0.3	1	0	new / 0
Incidents · Banda Sea	1	0.2	0	—	1.3× / 0.8
Quakes · Indian Ocean	1	0.1	1	0	0.3× / 3
Nav aids · Strait of Gibraltar	1	0.1	0	—	2.5× / 0.4
Nav aids · Gulf of Mexicolong running	0	254	8	728	0.0× / 2.6
Wrecks · The Northwestern Passageslong running	0	217	7	575	— / 0
Wrecks · Arabian Sea	0	186	6	314	0.0× / 0.2
Volcanic · Philippine Sealong running	0	186	6	833	0.0× / 0.2
Exercises · Aegean Sea	0	155	5	88	0.0× / 16.6
Surveys · The Northwestern Passages	0	155	5	224	— / 0
Wrecks · South Atlantic Ocean	0	139	4	308	0.0× / 1
Surveys · Kara Sea	0	124	4	263	— / 0
Other · Arabian Sealong running	0	119	3	568	0.0× / 0.2
Nav aids · Bay of Biscay	0	93	3	245	— / 0
Other · Coral Sea	0	93	3	345	0.0× / 1.6
Wrecks · South China Sealong running	0	93	3	1,485	0.0× / 0.8
Wrecks · North Atlantic Oceanlong running	0	71.7	2	674	0.0× / 0.2
Surveys · Barentsz Sea	0	62	2	263	0.0× / 0.2
Mines · Black Sealong running	0	62	2	400	— / 0
Surveys · Gulf of Mexico	0	62	2	120	0.0× / 0.6
Wrecks · Hudson Bay	0	62	2	154	— / 0
Nav aids · Persian Gulf	0	62	2	311	0.0× / 0.6
Nav aids · Andaman or Burma Sealong running	0	58.5	1	379	0.0× / 0.8
Other · South Atlantic Ocean	0	55.7	1	208	0.0× / 0.6
Exercises · Ionian Sea	0	40.8	1	88	— / 0
Nav aids · Gulf of Californialong running	0	40.7	1	773	— / 0
Wrecks · North Pacific Ocean	0	40.7	1	242	— / 0
Other · Gulf of Mexico	0	33.6	1	59	0.0× / 0.6
Missiles · Aegean Sea	0	31	1	88	0.0× / 0.2
Nav aids · Arctic Ocean	0	31	1	191	— / 0
Surveys · Arctic Ocean	0	31	1	201	— / 0
Nav aids · Barentsz Sea	0	31	1	139	— / 0
Debris · Bay of Biscay	0	31	1	205	— / 0

Cite: seahazards.com Sea Ledger, 2023-03, 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.