Sea Ledger, November 2021

2021-11-01 to 2021-11-30 · archive

issued: 622
warning-days in force: 11,503
in force at month end: 392
sea × type cells: 233

baseline: same month, previous 5 years (2020-11, 2019-11, 2018-11, 2017-11, 2016-11)

By type

type	issued	warning-days	in force at end
Exercises	121	1,406	50
Icebergs	91	106.1	6
Incidents	86	747.8	24
Surveys	65	2,068.7	70
Nav aids	62	3,209.9	108
Missiles	52	371.5	10
Quakes	31	89.6	5
Cable ops	26	398.3	14
Derelicts	19	184.8	8
Towing	19	20	0
Debris	14	41.7	1
Other	13	554.9	17
Spills	13	151	6
Containers	5	12.2	0
Wrecks	3	1,540.2	53
Piracy	1	2	0
Ordnance	1	79.3	3
Volcanic	0	360	12
Structures	0	60	2
Restricted	0	69	2
Mines	0	30	1

By sea and type · 200 cells, most issued first

cell	issued	warning-days	at end	longest d	vs 5 y
Icebergs · Southern Oceansurge	55	54.9	2	30	3.2× / 17.4
Incidents · South China Sealong running	26	277.6	6	603	0.9× / 28
Icebergs · Labrador Sea	23	27	2	30	1.4× / 16.6
Surveys · South Atlantic Ocean	21	147.4	5	44	1.4× / 14.6
Exercises · South Pacific Oceansurge	19	80.9	3	38	2.4× / 7.8
Towing · North Pacific Oceannew	19	20	0	—	new / 0
Exercises · Black Sea	18	344.8	9	92	1.3× / 13.8
Exercises · North Pacific Ocean	18	123.5	6	201	0.8× / 23.2
Missiles · North Atlantic Ocean	18	102.7	4	41	1.9× / 9.4
Nav aids · North Sea	15	224.4	10	96	1.4× / 11
Exercises · Arabian Sea	15	101.1	4	32	1.6× / 9.4
Surveys · Persian Gulfsurge	14	268.7	9	316	2.8× / 5
Exercises · South Atlantic Ocean	12	178.2	3	38	0.8× / 14.8
Exercises · Bay of Bengal	12	91.3	4	32	0.9× / 13
Incidents · North Pacific Ocean	9	115.6	2	35	0.5× / 18.6
Nav aids · South Atlantic Ocean	8	196.3	8	117	1.0× / 8
Missiles · South Pacific Ocean	8	60.7	0	—	1.3× / 6
Quakes · North Pacific Ocean	8	20.2	2	21	1.5× / 5.4
Cable ops · North Atlantic Ocean	7	75.4	4	97	1.8× / 3.8
Incidents · Indian Ocean	7	40.5	2	37	1.8× / 4
Surveys · Caribbean Seasurge	7	30.8	3	102	7.0× / 1
Cable ops · Celtic Seasurge	7	25.5	0	—	4.4× / 1.6
Icebergs · Davis Strait	7	8.1	0	—	0.8× / 9.2
Nav aids · North Pacific Ocean	6	265.7	10	360	1.6× / 3.8
Derelicts · Indian Ocean	6	22.9	1	18	1.5× / 4
Quakes · South Pacific Ocean	6	20.2	0	—	0.4× / 15.2
Icebergs · Indian Oceannew	6	16.1	2	23	new / 0
Missiles · Indian Ocean	6	14.3	1	31	1.4× / 4.2
Nav aids · North Atlantic Oceanlong running	5	350.8	11	843	0.9× / 5.4
Exercises · Mediterranean Sea - Eastern Basin	5	77.2	4	165	0.3× / 19
Exercises · North Atlantic Ocean	5	57.6	4	96	1.0× / 5
Missiles · Barentsz Sea	5	41.8	0	—	0.6× / 8.6
Incidents · South Atlantic Ocean	5	35.7	2	28	0.8× / 6.2
Incidents · Arabian Seasurge	5	35.1	2	26	2.1× / 2.4
Incidents · South Pacific Ocean	5	17.8	2	28	0.7× / 7
Debris · Indian Oceansurge	5	14.5	1	23	6.3× / 0.8
Incidents · Timor Seasurge	5	12.3	0	—	5.0× / 1
Incidents · Bay of Bengalsurge	4	48.7	1	32	20× / 0.2
Surveys · Arabian Sea	4	48.5	4	28	0.8× / 5.2
Exercises · Mediterranean Sea - Western Basinsurge	4	46.4	1	38	2.5× / 1.6
Spills · North Pacific Ocean	4	40	2	44	1.7× / 2.4
Missiles · South Atlantic Oceansurge	4	22.3	0	—	10× / 0.4
Derelicts · North Atlantic Ocean	4	12	0	—	1.1× / 3.6
Surveys · Indian Ocean	3	143.8	3	287	1.4× / 2.2
Surveys · Mediterranean Sea - Eastern Basin	3	113	5	102	0.6× / 4.8
Surveys · Bay of Bengal	3	59.6	1	96	0.8× / 3.8
Exercises · Laccadive Sea	3	37.7	2	33	1.0× / 3
Spills · The Coastal Waters of Southeast Alaska and British Columbiasurge	3	36	1	40	7.5× / 0.4
Incidents · Gulf of Thailand	3	26.6	1	21	1.4× / 2.2
Incidents · Java Sea	3	21.9	1	23	1.9× / 1.6
Spills · Gulf of Mexico	3	21	2	26	0.6× / 4.8
Missiles · Japan Seasurge	3	20.9	2	13	2.5× / 1.2
Quakes · South Atlantic Ocean	3	9	0	—	1.1× / 2.6
Debris · Coral Seanew	3	7	0	—	new / 0
Nav aids · Inner Seas off the West Coast of Scotland	3	6.2	0	—	0.8× / 4
Incidents · North Atlantic Ocean	3	3.1	0	—	0.2× / 13
Quakes · Bismarck Seasurge	3	1.6	3	0	5.0× / 0.6
Nav aids · Caribbean Sealong running	2	373.3	13	414	0.8× / 2.6
Nav aids · South Pacific Oceanlong running	2	294.2	8	449	0.6× / 3.2
Wrecks · Bay of Bengal	2	92.8	4	159	10× / 0.2
Nav aids · Tasman Sea	2	44.8	1	277	10× / 0.2
Cable ops · North Pacific Ocean	2	39	3	257	2.0× / 1
Incidents · Laccadive Sea	2	37.5	1	29	0.8× / 2.6
Derelicts · Bay of Bengal	2	36	1	77	0.6× / 3.6
Nav aids · Coral Sea	2	35	1	166	0.6× / 3.2
Nav aids · Great Australian Bight	2	33.9	0	—	2.5× / 0.8
Other · North Pacific Ocean	2	31.4	1	242	0.3× / 6.6
Spills · North Atlantic Ocean	2	29	1	41	0.6× / 3.2
Nav aids · Southern Ocean	2	26	2	19	10× / 0.2
Missiles · Norwegian Sea	2	23.1	1	32	3.3× / 0.6
Exercises · Barentsz Sea	2	18.1	0	—	1.7× / 1.2
Other · South Atlantic Ocean	2	16.2	1	13	1.4× / 1.4
Surveys · Mediterranean Sea - Western Basin	2	16.1	1	21	5.0× / 0.4
Cable ops · Eastern China Sea	2	13	0	—	2.0× / 1
Cable ops · Java Seanew	2	9.4	0	—	new / 0
Derelicts · South Pacific Ocean	2	9.2	1	13	0.8× / 2.4
Debris · South Atlantic Oceannew	2	8.2	0	—	new / 0
Quakes · Indian Ocean	2	7.4	0	—	1.0× / 2
Missiles · Philippine Sea	2	7	0	—	5.0× / 0.4
Quakes · Coral Sea	2	6	0	—	1.1× / 1.8
Other · Coral Sea	2	6	0	—	3.3× / 0.6
Containers · Red Seanew	2	6	0	—	new / 0
Debris · Timor Sea	2	6	0	—	0.6× / 3.6
Containers · Celtic Sea	2	3.2	0	—	10× / 0.2
Nav aids · The Coastal Waters of Southeast Alaska and British Columbia	2	2.8	1	8	1.4× / 1.4
Exercises · Alboran Seanew	2	0.6	1	0	new / 0
Incidents · Tasman Sea	2	0.2	0	—	1.4× / 1.4
Surveys · North Atlantic Ocean	1	480.8	13	334	0.1× / 7
Nav aids · Mediterranean Sea - Western Basinlong running	1	222.1	7	508	2.5× / 0.4
Nav aids · Arabian Sea	1	128.6	4	182	0.8× / 1.2
Nav aids · Bay of Bengallong running	1	91.5	2	538	1.3× / 0.8
Nav aids · Indian Ocean	1	91.4	3	234	1.0× / 1
Ordnance · North Sealong running	1	79.3	3	778	1.0× / 1
Other · Arafura Sea	1	63	2	237	new / 0
Other · North Atlantic Ocean	1	61.4	2	64	1.0× / 1
Surveys · South Pacific Oceanlong running	1	54.9	2	790	0.6× / 1.6
Nav aids · Andaman or Burma Sea	1	49.6	2	330	1.7× / 0.6
Nav aids · English Channel	1	35.2	2	95	0.2× / 4.2
Missiles · North Pacific Ocean	1	35.1	1	168	0.2× / 4.8
Nav aids · Persian Gulflong running	1	34.9	1	594	5.0× / 0.2
Derelicts · Caribbean Sea	1	34.3	1	245	0.6× / 1.6
Nav aids · Arafura Sea	1	32.9	1	40	5.0× / 0.2
Surveys · Barentsz Sea	1	32.7	1	46	0.7× / 1.4
Other · Caribbean Sea	1	30.9	1	33	1.3× / 0.8
Cable ops · Philippine Sea	1	26.5	1	26	0.7× / 1.4
Surveys · Bass Strait	1	23.1	1	23	5.0× / 0.2
Cable ops · Barentsz Sea	1	21.3	1	21	new / 0
Other · Mediterranean Sea - Western Basin	1	21.2	1	21	5.0× / 0.2
Incidents · Bering Sea	1	17.6	1	17	2.5× / 0.4
Cable ops · South China Sea	1	17.5	1	17	0.6× / 1.6
Spills · Gulf of Alaska	1	17	0	—	2.5× / 0.4
Surveys · Ligurian Sea	1	16.5	0	—	5.0× / 0.2
Other · Gulf of Mexico	1	16.3	1	16	2.5× / 0.4
Cable ops · English Channel	1	15.2	0	—	2.5× / 0.4
Incidents · Singapore Strait	1	13.5	1	13	1.7× / 0.6
Nav aids · Celtic Sea	1	12.7	0	—	0.7× / 1.4
Exercises · Tasman Sea	1	10.7	0	—	new / 0
Exercises · Coral Sea	1	10.3	0	—	0.8× / 1.2
Cable ops · Yellow Sea	1	8	0	—	new / 0
Missiles · Arctic Ocean	1	7.5	0	—	1.0× / 1
Wrecks · Kara Sea	1	7.4	1	7	5.0× / 0.2
Exercises · Indian Ocean	1	5.9	0	—	0.6× / 1.6
Incidents · Gulf of Aden	1	5.2	0	—	new / 0
Surveys · Timor Sea	1	5.1	0	—	5.0× / 0.2
Derelicts · Laccadive Sea	1	5	0	—	0.8× / 1.2
Quakes · Banda Sea	1	4.5	0	—	1.3× / 0.8
Cable ops · Bay of Bengal	1	4.5	1	4	new / 0
Other · Gulf of Alaska	1	4	0	—	new / 0
Missiles · Laccadive Sea	1	3.4	0	—	1.3× / 0.8
Debris · Arafura Sea	1	3	0	—	0.6× / 1.6
Quakes · Arafura Sea	1	3	0	—	new / 0
Debris · Caribbean Sea	1	3	0	—	new / 0
Quakes · Ceram Sea	1	3	0	—	new / 0
Containers · Mediterranean Sea - Western Basin	1	3	0	—	5.0× / 0.2
Quakes · Molukka Sea	1	3	0	—	0.6× / 1.8
Incidents · Mozambique Channel	1	3	0	—	5.0× / 0.2
Quakes · Philippine Sea	1	3	0	—	1.0× / 1
Quakes · Solomon Sea	1	3	0	—	1.7× / 0.6
Derelicts · South Atlantic Ocean	1	3	0	—	0.6× / 1.6
Quakes · Tasman Sea	1	3	0	—	2.5× / 0.4
Missiles · South China Sea	1	2.7	0	—	5.0× / 0.2
Exercises · Philippine Sea	1	2.3	0	—	0.2× / 5
Other · Timor Sea	1	2.3	0	—	new / 0
Surveys · Tasman Sea	1	1.8	1	1	2.5× / 0.4
Incidents · Eastern China Sea	1	1.6	1	1	0.7× / 1.4
Derelicts · Gulf of Oman	1	1.6	1	1	new / 0
Nav aids · Hudson Strait	1	1.6	1	1	new / 0
Nav aids · Irish Sea and St. George's Channel	1	1.5	0	—	0.6× / 1.8
Surveys · Andaman or Burma Sea	1	1.4	1	1	1.0× / 1
Exercises · Mozambique Channel	1	1.3	1	1	new / 0
Exercises · Caribbean Sea	1	1.2	1	1	1.0× / 1
Derelicts · Tasman Sea	1	0.8	1	0	5.0× / 0.2
Piracy · North Atlantic Ocean	1	0.1	0	—	new / 0
Incidents · Persian Gulf	1	0.1	0	—	1.7× / 0.6
Incidents · Coral Sea	1	0	0	—	0.2× / 4.6
Wrecks · North Atlantic Oceanlong running	0	300	10	1,044	0.0× / 1
Volcanic · Philippine Sea	0	270	9	347	— / 0
Nav aids · Gulf of Mexico	0	240	8	360	0.0× / 1.4
Wrecks · South China Sealong running	0	240	8	1,017	0.0× / 2.2
Wrecks · South Atlantic Ocean	0	150	5	316	— / 0
Wrecks · Arabian Sealong running	0	120	4	798	0.0× / 0.6
Wrecks · The Northwestern Passages	0	120	4	91	— / 0
Exercises · Aegean Sea	0	93.3	3	322	0.0× / 15.2
Exercises · Ionian Sea	0	90	3	322	— / 0
Wrecks · Laccadive Sea	0	90	3	195	— / 0
Nav aids · Mozambique Channellong running	0	90	3	412	0.0× / 0.4
Wrecks · North Pacific Oceanlong running	0	90	3	971	0.0× / 0.6
Wrecks · Persian Gulflong running	0	90	3	389	0.0× / 0.6
Surveys · Sea of Okhotsk	0	75	2	103	0.0× / 0.6
Surveys · Arctic Oceanlong running	0	65	2	407	0.0× / 0.6
Other · English Channel	0	62.9	1	66	0.0× / 0.6
Surveys · Black Sea	0	60	2	265	0.0× / 1.6
Wrecks · Caribbean Sea	0	60	2	252	0.0× / 1.2
Wrecks · English Channel	0	60	2	326	0.0× / 1
Surveys · Hudson Bay	0	60	2	104	— / 0
Wrecks · Inner Seas off the West Coast of Scotlandlong running	0	60	2	417	0.0× / 0.4
Surveys · Kara Sea	0	60	2	104	— / 0
Nav aids · Mediterranean Sea - Eastern Basin	0	60	2	204	0.0× / 0.4
Other · Persian Gulflong running	0	60	2	512	0.0× / 0.2
Structures · South Atlantic Ocean	0	60	2	180	0.0× / 0.4
Surveys · South China Sealong running	0	60	2	810	0.0× / 0.4
Surveys · The Northwestern Passages	0	60	2	76	0.0× / 0.2
Restricted · South Atlantic Oceanlong running	0	39	1	698	0.0× / 0.6
Nav aids · The Northwestern Passages	0	38.5	1	70	0.0× / 0.2
Cable ops · Arabian Sea	0	31.3	0	—	0.0× / 0.8
Missiles · Aegean Sea	0	30	1	322	0.0× / 0.8
Derelicts · Arabian Sea	0	30	1	165	0.0× / 0.6
Other · Arabian Sea	0	30	1	82	— / 0
Surveys · Baffin Bay	0	30	1	112	— / 0
Nav aids · Balearic (Iberian Sea)	0	30	1	37	— / 0
Surveys · Balearic (Iberian Sea)	0	30	1	74	— / 0
Nav aids · Barentsz Sea	0	30	1	64	— / 0
Surveys · Bay of Biscay	0	30	1	148	0.0× / 0.2
Other · Bering Sea	0	30	1	61	0.0× / 0.4
Surveys · Bering Sea	0	30	1	137	— / 0
Cable ops · Black Sea	0	30	1	308	— / 0
Nav aids · Black Sea	0	30	1	229	— / 0
Volcanic · Caribbean Sea	0	30	1	232	— / 0
Surveys · Davis Strait	0	30	1	118	— / 0
Nav aids · Gulf of California	0	30	1	287	— / 0

Cite: seahazards.com Sea Ledger, 2021-11, 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.