Sea Ledger, November 2023

2023-11-01 to 2023-11-30 · archive

issued: 720
warning-days in force: 14,726
in force at month end: 488
sea × type cells: 244

baseline: same month, previous 5 years (2022-11, 2021-11, 2020-11, 2019-11, 2018-11)

By type

type	issued	warning-days	in force at end
Exercises	163	1,294.3	44
Incidents	132	1,272.2	52
Icebergs	90	97.4	4
Surveys	71	2,502.2	86
Missiles	64	468.6	12
Nav aids	59	4,832.3	150
Quakes	45	143	4
Cable ops	27	688.8	24
Other	19	570.9	21
Spills	16	237.1	9
Derelicts	13	117.7	2
Wrecks	9	1,685.1	54
Towing	7	7.2	0
Debris	3	63.3	1
Volcanic	1	320.6	11
Piracy	1	4.8	0
Mines	0	120	4
Structures	0	120	4
Restricted	0	60	2
War risk	0	30	1
Ordnance	0	90	3

By sea and type · 200 cells, most issued first

cell	issued	warning-days	at end	longest d	vs 5 y
Incidents · North Atlantic Oceansurge	35	406.6	14	48	2.6× / 13.6
Incidents · South China Sea	34	212.7	15	44	1.6× / 20.6
Icebergs · Southern Ocean	30	31.9	1	30	0.9× / 33.8
Icebergs · South Atlantic Ocean	29	27.8	1	30	1.5× / 18.8
Exercises · Bay of Bengal	19	107.7	4	34	1.5× / 12.8
Exercises · North Pacific Ocean	15	211.5	10	65	0.5× / 29.2
Exercises · South Pacific Ocean	15	56.5	1	31	1.1× / 13.8
Surveys · South Atlantic Ocean	14	229.3	11	189	0.7× / 21
Surveys · South Pacific Oceansurge	14	165.7	5	254	12× / 1.2
Exercises · Celtic Seasurge	14	20	0	—	4.1× / 3.4
Exercises · North Atlantic Oceansurge	13	129.1	3	95	2.2× / 5.8
Missiles · Indian Oceansurge	13	104	2	62	2.4× / 5.4
Icebergs · Labrador Sea	13	15.2	2	31	0.6× / 21.2
Exercises · Arabian Sea	12	89.1	2	37	1.0× / 11.6
Missiles · North Atlantic Ocean	12	56.9	1	61	0.8× / 14.2
Exercises · South Atlantic Ocean	11	76.4	5	35	0.8× / 14.2
Cable ops · Caribbean Seasurge	11	51.7	2	32	14× / 0.8
Exercises · Bay of Biscaysurge	11	13.4	1	16	11× / 1
Surveys · Arabian Sea	9	272.3	11	58	0.9× / 9.6
Missiles · Barentsz Sea	9	73.1	1	32	1.2× / 7.6
Incidents · Indian Ocean	9	60	3	35	1.7× / 5.4
Missiles · South Pacific Ocean	9	53.9	2	72	1.6× / 5.8
Icebergs · Davis Strait	9	10.6	0	—	1.0× / 8.8
Surveys · North Atlantic Ocean	8	341.5	10	333	1.5× / 5.4
Nav aids · North Pacific Oceansurgelong running	8	216.1	7	603	2.9× / 2.8
Incidents · South Atlantic Ocean	8	123.3	5	35	1.6× / 5
Exercises · Philippine Seasurge	8	49.2	3	29	2.7× / 3
Exercises · Andaman or Burma Seasurge	8	30.2	0	—	5.0× / 1.6
Quakes · North Pacific Ocean	8	23.7	1	22	1.5× / 5.2
Icebergs · Hudson Straitsurge	8	9.2	0	—	40× / 0.2
Nav aids · North Atlantic Oceanlong running	7	329.7	11	959	1.2× / 5.8
Exercises · Black Sealong running	7	107.2	3	617	0.5× / 14.6
Missiles · North Pacific Oceansurge	7	79.4	2	275	2.2× / 3.2
Incidents · North Pacific Ocean	7	74.6	2	47	0.6× / 12.6
Quakes · Banda Seasurge	7	21	0	—	18× / 0.4
Towing · North Pacific Ocean	7	7.2	0	—	0.9× / 8
Surveys · Indian Oceansurge	6	166.4	5	279	4.3× / 1.4
Exercises · Celebes Seasurge	6	33.1	1	20	30× / 0.2
Quakes · South Pacific Ocean	6	22.7	1	30	0.6× / 10.2
Quakes · Bismarck Seasurge	6	18	0	—	10× / 0.6
Nav aids · South Atlantic Oceanlong running	5	1,230	41	475	0.6× / 8.6
Surveys · Persian Gulflong running	5	209.4	8	468	0.6× / 8.8
Nav aids · North Sea	5	91.8	1	160	0.5× / 9.8
Nav aids · English Channel	5	77.2	3	27	1.7× / 3
Cable ops · North Atlantic Ocean	5	68.1	4	174	0.9× / 5.4
Other · South Atlantic Oceansurge	5	55.5	4	212	3.1× / 1.6
Nav aids · Inner Seas off the West Coast of Scotland	5	51.3	1	63	1.2× / 4.2
Incidents · Philippine Seasurge	5	49.2	3	21	2.3× / 2.2
Missiles · Philippine Seasurge	5	28.5	2	31	8.3× / 0.6
Derelicts · South Pacific Oceansurge	5	13.9	0	—	2.5× / 2
Nav aids · South Pacific Oceanlong running	4	372.5	9	616	0.9× / 4.4
Nav aids · Coral Sea	4	188.2	5	221	1.3× / 3
Cable ops · Arabian Seasurge	4	113.7	3	77	6.7× / 0.6
Surveys · Gulf of Mexicosurge	4	82.5	3	214	20× / 0.2
Spills · North Atlantic Oceanlong running	4	66	5	497	1.5× / 2.6
Surveys · Bass Straitsurge	4	48.7	1	238	10× / 0.4
Exercises · Laccadive Sea	4	41.3	1	30	1.2× / 3.4
Incidents · Coral Sea	4	19.6	1	45	1.2× / 3.4
Quakes · Coral Seasurge	4	17.9	1	32	3.3× / 1.2
Exercises · Indian Oceansurge	4	15.5	0	—	2.5× / 1.6
Exercises · Coral Seasurge	4	15.1	0	—	5.0× / 0.8
Wrecks · Persian Gulfsurgelong running	3	133.2	4	652	3.8× / 0.8
Surveys · Laccadive Seanewlong running	3	84.5	3	656	new / 0
Spills · Gulf of Mexico	3	58	0	—	0.6× / 5
Cable ops · Malacca Straitsurge	3	53	1	62	5.0× / 0.6
Incidents · Caribbean Seasurge	3	44.8	1	21	3.0× / 1
Incidents · Mediterranean Sea - Eastern Basin	3	43.8	1	37	1.1× / 2.6
Incidents · Bay of Bengal	3	32.7	0	—	1.7× / 1.8
Spills · Bering Seanew	3	32	1	29	new / 0
Incidents · South Pacific Ocean	3	29.4	0	—	0.5× / 5.6
Incidents · Laccadive Sea	3	23.6	0	—	0.9× / 3.2
Missiles · Gulf of Mexiconew	3	13.7	0	—	new / 0
Exercises · Sulu Seanew	3	13.4	1	11	new / 0
Derelicts · Caribbean Seasurge	3	6	0	—	2.1× / 1.4
Wrecks · South Atlantic Oceanlong running	2	206.7	7	552	10× / 0.2
Nav aids · Celtic Sea	2	94.6	2	80	1.7× / 1.2
Other · Caribbean Sealong running	2	94.2	3	763	3.3× / 0.6
Nav aids · Hudson Baylong running	2	59	1	442	5.0× / 0.4
Nav aids · The Northwestern Passages	2	58.8	1	113	10× / 0.2
Exercises · Caribbean Sea	2	32.4	1	69	1.7× / 1.2
Other · North Pacific Ocean	2	26.5	1	37	0.3× / 7.2
Spills · North Pacific Ocean	2	25	1	19	1.3× / 1.6
Incidents · Arabian Sea	2	20.3	2	17	0.6× / 3.4
Incidents · Java Sea	2	19.9	1	13	1.3× / 1.6
Other · North Atlantic Ocean	2	17.7	1	23	1.7× / 1.2
Exercises · Barentsz Sea	2	8	0	—	1.1× / 1.8
Quakes · Celebes Sea	2	6	0	—	5.0× / 0.4
Quakes · Indian Ocean	2	6	0	—	1.3× / 1.6
Quakes · Philippine Sea	2	6	0	—	2.5× / 0.8
Quakes · Solomon Sea	2	6	0	—	1.1× / 1.8
Exercises · Mozambique Channel	2	5.6	0	—	10× / 0.2
Quakes · South Atlantic Ocean	2	3.7	1	24	0.7× / 3
Nav aids · Caribbean Sealong running	1	867.2	29	1,017	0.3× / 3.4
Volcanic · Philippine Sealong running	1	290.6	10	1,077	new / 0
Nav aids · Gulf of Mexicolong running	1	241.1	8	972	1.3× / 0.8
Wrecks · Arabian Sealong running	1	174.6	6	417	2.5× / 0.4
Wrecks · Caribbean Sea	1	149.2	4	263	1.7× / 0.6
Nav aids · Laccadive Sealong running	1	122.3	4	534	2.5× / 0.4
Surveys · Kara Sealong running	1	113.4	4	507	new / 0
Nav aids · Beaufort Sealong running	1	104.6	3	476	new / 0
Surveys · Caribbean Sealong running	1	61.5	2	396	0.4× / 2.4
Incidents · Gulf of Mexico	1	46.4	1	45	0.6× / 1.6
Wrecks · Southern Ocean	1	42.6	0	—	new / 0
Cable ops · South Atlantic Ocean	1	39.1	2	160	2.5× / 0.4
Nav aids · Bay of Biscaylong running	1	38.7	2	489	new / 0
Other · Arafura Sea	1	30.5	1	107	5.0× / 0.2
Nav aids · Davis Strait	1	28.1	1	28	0.7× / 1.4
Spills · The Coastal Waters of Southeast Alaska and British Columbia	1	28	1	37	0.8× / 1.2
Debris · South Pacific Ocean	1	27.4	0	—	5.0× / 0.2
Other · Coral Sea	1	23.9	1	23	1.7× / 0.6
Cable ops · Celebes Sea	1	22.4	1	22	new / 0
Wrecks · English Channel	1	18.8	1	18	1.3× / 0.8
Exercises · South China Sea	1	17	1	16	0.8× / 1.2
Surveys · Gulf of Guinea	1	16.3	1	16	5.0× / 0.2
Incidents · Bay of Biscay	1	15.2	0	—	5.0× / 0.2
Incidents · Ionian Sea	1	14.3	0	—	new / 0
Spills · Caribbean Sea	1	14	0	—	5.0× / 0.2
Cable ops · Philippine Sea	1	12.5	1	12	1.3× / 0.8
Other · South Pacific Ocean	1	11.8	1	11	2.5× / 0.4
Surveys · Alboran Sea	1	11.2	0	—	new / 0
Spills · Arabian Sea	1	11.1	0	—	5.0× / 0.2
Incidents · Mediterranean Sea - Western Basin	1	9.8	1	45	1.3× / 0.8
Incidents · Tyrrhenian Sea	1	8.8	1	46	5.0× / 0.2
Other · Mediterranean Sea - Eastern Basin	1	8.2	1	8	1.3× / 0.8
Missiles · Bay of Bengal	1	6	0	—	1.7× / 0.6
Missiles · Arabian Sea	1	5.6	0	—	new / 0
Exercises · Baltic Sea	1	5.3	0	—	5.0× / 0.2
Piracy · Red Sea	1	4.8	0	—	2.5× / 0.4
Derelicts · Indian Ocean	1	4.3	0	—	0.2× / 4.4
Other · Celtic Sea	1	4	0	—	2.5× / 0.4
Missiles · East Siberian Sea	1	3.7	1	3	new / 0
Nav aids · Bristol Channel	1	3.5	0	—	5.0× / 0.2
Exercises · Red Sea	1	3.3	1	36	2.5× / 0.4
Incidents · Black Sea	1	3	0	—	0.8× / 1.2
Debris · Celtic Sea	1	3	0	—	5.0× / 0.2
Spills · Gulf of Alaska	1	3	1	3	2.5× / 0.4
Derelicts · Gulf of Mexico	1	3	0	—	2.5× / 0.4
Quakes · Molukka Sea	1	3	0	—	0.6× / 1.8
Other · Mozambique Channel	1	3	0	—	new / 0
Quakes · North Atlantic Ocean	1	3	0	—	0.7× / 1.4
Quakes · Savu Sea	1	3	0	—	new / 0
Quakes · Southern Ocean	1	3	0	—	1.0× / 1
Derelicts · Timor Sea	1	3	0	—	5.0× / 0.2
Debris · North Pacific Ocean	1	2.9	0	—	5.0× / 0.2
Missiles · Laccadive Sea	1	2.8	0	—	1.3× / 0.8
Icebergs · Laptev Sea	1	2.7	0	—	0.7× / 1.4
Cable ops · Eastern China Sea	1	2.5	1	2	1.7× / 0.6
Missiles · Norwegian Sea	1	2.4	0	—	0.7× / 1.4
Missiles · Tasman Sea	1	2.4	0	—	new / 0
Other · Davis Strait	1	1.5	0	—	new / 0
Incidents · Singapore Strait	1	1.5	1	1	2.5× / 0.4
Nav aids · Baltic Sea	1	0.6	0	—	new / 0
Nav aids · Irish Sea and St. George's Channel	1	0.6	0	—	0.5× / 2
Nav aids · Kattegat	1	0.5	0	—	new / 0
Derelicts · South China Sea	1	0.4	0	—	1.3× / 0.8
Other · Gulf of Mexico	1	0.2	0	—	1.7× / 0.6
Derelicts · Tasman Sea	1	0.2	0	—	5.0× / 0.2
Incidents · Timor Sea	1	0.2	0	—	0.6× / 1.6
Incidents · Arafura Sea	1	0.1	0	—	1.3× / 0.8
Incidents · Hudson Strait	1	0.1	0	—	new / 0
Incidents · Tasman Sea	1	0.1	0	—	1.0× / 1
Surveys · The Northwestern Passageslong running	0	210	7	468	0.0× / 0.2
Cable ops · Persian Gulf	0	180	6	253	0.0× / 0.2
Wrecks · The Northwestern Passageslong running	0	180	6	819	— / 0
Exercises · Aegean Sea	0	150	5	332	0.0× / 11.2
Mines · Black Sealong running	0	120	4	644	— / 0
Wrecks · Hudson Baylong running	0	120	4	398	— / 0
Wrecks · North Atlantic Ocean	0	120	4	43	0.0× / 0.4
Ordnance · Bay of Biscay	0	90	3	164	— / 0
Surveys · Chukchi Sea	0	90	3	113	— / 0
Nav aids · Indian Ocean	0	90	3	99	0.0× / 1
Nav aids · Persian Gulflong running	0	90	3	555	0.0× / 0.8
Wrecks · South China Sealong running	0	90	3	1,729	0.0× / 1.6
Surveys · Arctic Ocean	0	61	2	101	0.0× / 0.6
Nav aids · Arabian Sealong running	0	60	2	764	0.0× / 1
Wrecks · Bay of Bengal	0	60	2	127	0.0× / 0.6
Other · Bay of Biscay	0	60	2	316	— / 0
Nav aids · Bering Sea	0	60	2	342	— / 0
Surveys · Black Sea	0	60	2	301	0.0× / 1
Wrecks · Coral Sealong running	0	60	2	517	— / 0
Nav aids · Hudson Strait	0	60	2	139	0.0× / 0.2
Wrecks · Kara Sea	0	60	2	44	0.0× / 0.6
Wrecks · Laccadive Sea	0	60	2	286	— / 0
Other · Persian Gulf	0	60	2	287	0.0× / 0.2
Structures · South Atlantic Oceanlong running	0	60	2	489	0.0× / 0.4
Wrecks · South Pacific Ocean	0	60	2	241	0.0× / 0.2
Cable ops · North Pacific Ocean	0	55	1	42	0.0× / 1
Surveys · Bay of Bengal	0	50.4	1	70	0.0× / 4.6
Surveys · Barentsz Sea	0	32	1	63	0.0× / 0.6
Derelicts · North Atlantic Ocean	0	31.8	1	31	0.0× / 4.4
Missiles · Aegean Sea	0	30	1	332	0.0× / 0.4
Nav aids · Andaman or Burma Sea	0	30	1	206	0.0× / 0.4
Other · Arabian Sea	0	30	1	67	— / 0
Wrecks · Arafura Sea	0	30	1	213	— / 0
Nav aids · Arctic Ocean	0	30	1	48	— / 0
Nav aids · Barentsz Sealong running	0	30	1	383	0.0× / 0.2
Nav aids · Bass Strait	0	30	1	50	0.0× / 1.6
Other · Bay of Bengal	0	30	1	117	— / 0
Debris · Bay of Biscaylong running	0	30	1	449	— / 0
Surveys · Beaufort Sea	0	30	1	113	— / 0

Cite: seahazards.com Sea Ledger, 2023-11, 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.