Sea Ledger, October 2021

2021-10-01 to 2021-10-31 · archive

issued: 697
warning-days in force: 11,696
in force at month end: 388
sea × type cells: 248

baseline: same month, previous 5 years (2020-10, 2019-10, 2018-10, 2017-10, 2016-10)

By type

type	issued	warning-days	in force at end
Exercises	172	1,532.8	56
Icebergs	90	102.4	4
Incidents	89	721.4	15
Surveys	79	2,277.5	78
Nav aids	71	3,115.8	107
Missiles	49	359.5	8
Quakes	32	89.6	5
Cable ops	20	422.3	12
Derelicts	19	167.7	7
Other	18	539.9	18
Spills	13	168	5
Towing	13	14.4	0
Debris	11	32.9	1
Wrecks	6	1,519.2	50
Volcanic	5	325.3	12
Piracy	5	33	2
Ordnance	3	84.7	2
Structures	1	62.5	2
Containers	1	3	0
Restricted	0	93	3
Mines	0	31	1

By sea and type · 200 cells, most issued first

cell	issued	warning-days	at end	longest d	vs 5 y
Icebergs · Southern Oceansurge	54	52.6	2	30	2.7× / 20
Exercises · Black Sea	36	274.2	15	62	1.7× / 21.2
Icebergs · Labrador Sea	30	35.2	1	32	1.0× / 29.8
Incidents · North Pacific Ocean	20	114.9	3	46	1.0× / 19.4
Exercises · South Pacific Oceansurge	20	101.5	4	39	3.1× / 6.4
Incidents · South China Sealong running	18	181.6	6	573	0.5× / 33.2
Exercises · South Atlantic Ocean	17	162.9	7	67	2.0× / 8.6
Surveys · South Atlantic Ocean	17	114.7	6	147	1.0× / 17
Exercises · Arabian Sea	15	76.6	2	32	1.6× / 9.2
Surveys · North Atlantic Ocean	14	590.9	22	304	1.8× / 8
Exercises · North Pacific Ocean	13	218.2	6	171	0.6× / 22.2
Exercises · Bay of Bengal	13	100	1	30	1.1× / 12.4
Exercises · North Atlantic Ocean	13	87.2	2	66	1.3× / 10.2
Missiles · North Atlantic Ocean	13	61	3	34	1.8× / 7.2
Towing · North Pacific Oceannew	13	14.4	0	—	new / 0
Surveys · Indian Oceansurge	11	149.8	5	257	5.5× / 2
Missiles · Barentsz Sea	11	86.7	1	34	1.2× / 9.2
Quakes · South Pacific Ocean	10	27.8	2	29	0.9× / 11.6
Nav aids · North Sea	9	183.8	6	66	1.1× / 8
Nav aids · North Atlantic Oceanlong running	8	334.7	12	813	1.1× / 7.4
Exercises · Mediterranean Sea - Eastern Basin	8	75.7	6	135	0.4× / 21.6
Incidents · Indian Ocean	8	43.3	1	37	1.7× / 4.6
Nav aids · South Atlantic Ocean	7	237.9	7	205	1.2× / 6
Surveys · Persian Gulf	7	149.2	8	286	1.8× / 4
Incidents · Arabian Seasurge	7	86.2	0	—	2.1× / 3.4
Missiles · Japan Seasurge	7	37.4	0	—	12× / 0.6
Nav aids · Indian Oceansurge	6	155.6	3	204	6.0× / 1
Cable ops · North Atlantic Ocean	6	111.5	2	67	0.7× / 9
Incidents · Laccadive Seasurge	6	84.5	0	—	3.0× / 2
Exercises · Andaman or Burma Seasurge	6	24.7	0	—	3.8× / 1.6
Nav aids · North Pacific Ocean	5	236	9	330	0.9× / 5.8
Volcanic · Philippine Seanew	5	232.3	9	317	new / 0
Spills · North Pacific Oceansurge	5	70	1	31	2.3× / 2.2
Incidents · Bay of Bengalsurge	5	65.9	2	35	13× / 0.4
Nav aids · South Pacific Oceanlong running	4	248.6	10	419	1.1× / 3.6
Surveys · Caribbean Seasurge	4	62	2	72	2.2× / 1.8
Surveys · Mediterranean Sea - Western Basinsurge	4	42	0	—	4.0× / 1
Incidents · South Pacific Ocean	4	32	0	—	0.5× / 8.4
Exercises · Japan Seasurge	4	20.9	0	—	2.9× / 1.4
Exercises · Indian Oceansurge	4	15.5	1	19	2.2× / 1.8
Quakes · North Pacific Ocean	4	12	0	—	0.7× / 6
Exercises · Philippine Sea	4	9.1	0	—	1.1× / 3.6
Derelicts · South Pacific Oceansurge	4	8.6	0	—	2.5× / 1.6
Nav aids · Inner Seas off the West Coast of Scotland	4	4.9	1	12	0.7× / 6
Nav aids · Mediterranean Sea - Western Basinsurgelong running	3	181.3	7	478	5.0× / 0.6
Surveys · South Pacific Oceansurgelong running	3	113.4	4	760	2.5× / 1.2
Surveys · Arabian Sea	3	87.3	0	—	0.7× / 4.6
Other · North Pacific Ocean	3	49.4	1	212	0.5× / 6.4
Exercises · Laccadive Sea	3	43.3	1	33	1.5× / 2
Surveys · Mediterranean Sea - Eastern Basin	3	41.1	4	72	0.4× / 8
Nav aids · Coral Sea	3	40.2	2	136	1.1× / 2.8
Spills · North Atlantic Ocean	3	39	1	19	1.7× / 1.8
Piracy · Gulf of Guinea	3	19	2	11	1.4× / 2.2
Missiles · Philippine Seasurge	3	12.5	0	—	15× / 0.2
Exercises · Coral Seasurge	3	10.5	0	—	3.0× / 1
Debris · North Atlantic Oceansurge	3	9	0	—	2.5× / 1.2
Derelicts · Indian Ocean	3	8	0	—	0.7× / 4.2
Missiles · Baffin Baysurge	3	6	0	—	15× / 0.2
Incidents · Timor Seasurge	3	4.7	1	28	2.5× / 1.2
Incidents · Coral Sea	3	0.3	0	—	0.8× / 3.6
Nav aids · Caribbean Sealong running	2	308.4	11	384	1.0× / 2
Nav aids · Arabian Sea	2	149	5	152	2.0× / 1
Wrecks · South Atlantic Ocean	2	139.4	5	286	2.5× / 0.8
Surveys · Sea of Okhotsk	2	79.6	3	73	1.3× / 1.6
Surveys · South China Sealong running	2	50.5	2	780	1.3× / 1.6
Other · English Channel	2	49.7	3	36	2.5× / 0.8
Missiles · North Pacific Ocean	2	46.8	1	138	0.4× / 5.2
Wrecks · Caribbean Sea	2	42.9	2	222	3.3× / 0.6
Cable ops · Indian Ocean	2	38.6	1	135	10× / 0.2
Cable ops · North Pacific Ocean	2	38.6	1	227	2.0× / 1
Nav aids · The Northwestern Passages	2	37.5	2	40	1.1× / 1.8
Other · Hudson Bay	2	33.1	2	41	5.0× / 0.4
Incidents · Solomon Sea	2	31.9	1	102	2.0× / 1
Exercises · Mediterranean Sea - Western Basin	2	29.1	1	34	1.1× / 1.8
Surveys · Ligurian Seanew	2	28.9	1	18	new / 0
Cable ops · Arabian Sea	2	28.6	2	14	2.0× / 1
Spills · The Coastal Waters of Southeast Alaska and British Columbia	2	28	1	41	2.0× / 1
Nav aids · Bass Strait	2	23.1	0	—	5.0× / 0.4
Cable ops · Eastern China Sea	2	17.5	0	—	2.5× / 0.8
Nav aids · Davis Strait	2	17.4	0	—	1.3× / 1.6
Incidents · North Atlantic Ocean	2	15.1	0	—	0.2× / 9.8
Missiles · Gulf of Guineanew	2	13.7	0	—	new / 0
Surveys · Timor Sea	2	11.9	0	—	10× / 0.2
Nav aids · Celtic Sea	2	10.4	0	—	1.1× / 1.8
Missiles · South Atlantic Ocean	2	9.5	0	—	3.3× / 0.6
Missiles · Norwegian Seanew	2	6.4	1	34	new / 0
Incidents · Caribbean Sea	2	6.3	0	—	0.5× / 4
Debris · Coral Seanew	2	6	0	—	new / 0
Quakes · Coral Sea	2	6	0	—	2.5× / 0.8
Debris · Indian Ocean	2	6	0	—	5.0× / 0.4
Icebergs · Laptev Sea	2	6	0	—	1.1× / 1.8
Quakes · Mediterranean Sea - Eastern Basinnew	2	6	0	—	new / 0
Quakes · Molukka Sea	2	6	0	—	5.0× / 0.4
Quakes · Philippine Sea	2	6	0	—	0.8× / 2.4
Missiles · Indian Ocean	2	5.6	1	5	0.8× / 2.4
Other · Indian Ocean	2	5.2	0	—	5.0× / 0.4
Debris · South Atlantic Ocean	2	4.8	1	4	5.0× / 0.4
Quakes · Indian Ocean	2	4.6	1	29	1.1× / 1.8
Other · Gulf of Alaskanew	2	4.1	0	—	new / 0
Derelicts · Laccadive Sea	2	4	1	25	1.3× / 1.6
Incidents · Bismarck Sea	2	3.8	0	—	1.0× / 2
Derelicts · English Channel	2	3.3	0	—	3.3× / 0.6
Quakes · Gulf of Alaska	2	3.3	1	20	10× / 0.2
Ordnance · Black Sea	2	3	0	—	5.0× / 0.4
Exercises · Barentsz Sea	2	2.9	1	16	0.8× / 2.4
Nav aids · Hudson Baynew	2	2.3	0	—	new / 0
Cable ops · Celtic Sea	2	2.1	0	—	2.0× / 1
Exercises · Red Sea	2	1.1	1	5	2.5× / 0.8
Incidents · Ceram Sea	2	0.5	0	—	10× / 0.2
Nav aids · Gulf of Mexico	1	248.8	8	330	0.3× / 4
Wrecks · South China Sealong running	1	240.5	8	987	0.7× / 1.4
Surveys · Kara Sea	1	111.9	2	109	0.8× / 1.2
Exercises · Aegean Sea	1	107.3	4	292	0.1× / 11.8
Wrecks · Laccadive Sea	1	87.6	3	165	5.0× / 0.2
Structures · South Atlantic Ocean	1	62.5	2	150	1.3× / 0.8
Surveys · The Northwestern Passages	1	55.9	2	46	2.5× / 0.4
Surveys · Barentsz Sea	1	43	1	194	1.0× / 1
Missiles · Black Sea	1	38	0	—	0.2× / 6.4
Other · Kara Sea	1	36.6	1	106	2.5× / 0.4
Derelicts · Caribbean Sea	1	32.7	2	215	2.5× / 0.4
Other · Bering Sea	1	31.7	1	31	1.3× / 0.8
Derelicts · South China Sea	1	31.2	2	76	5.0× / 0.2
Cable ops · Norwegian Sea	1	31	1	58	new / 0
Exercises · Alboran Sea	1	29	0	—	new / 0
Surveys · Laccadive Sea	1	18.4	0	—	1.7× / 0.6
Other · Gulf of Mexico	1	17.7	0	—	1.3× / 0.8
Surveys · North Pacific Ocean	1	17.7	1	31	0.7× / 1.4
Cable ops · North Sea	1	17.7	0	—	1.0× / 1
Incidents · South Atlantic Ocean	1	17	0	—	0.2× / 6.2
Spills · Gulf of Mexico	1	14	0	—	0.1× / 9.8
Ordnance · North Pacific Ocean	1	14	0	—	1.7× / 0.6
Nav aids · Strait of Gibraltar	1	12.9	1	12	1.3× / 0.8
Spills · Gulf of Alaska	1	11	1	11	1.7× / 0.6
Nav aids · Arafura Sea	1	10.9	1	10	1.0× / 1
Nav aids · Great Australian Bight	1	9.3	1	9	0.3× / 3.2
Other · South Atlantic Ocean	1	7.6	0	—	1.7× / 0.6
Nav aids · Balearic (Iberian Sea)	1	7.5	1	7	new / 0
Exercises · Chukchi Sea	1	7.3	0	—	new / 0
Piracy · Red Sea	1	7	0	—	5.0× / 0.2
Piracy · Singapore Strait	1	7	0	—	2.5× / 0.4
Cable ops · Bay of Biscay	1	6.5	1	6	new / 0
Spills · Bering Sea	1	6	1	6	2.5× / 0.4
Incidents · Bali Sea	1	5.9	1	5	new / 0
Missiles · Laccadive Sea	1	4.9	0	—	1.3× / 0.8
Other · The Coastal Waters of Southeast Alaska and British Columbia	1	4.3	0	—	5.0× / 0.2
Exercises · Caribbean Sea	1	3.5	0	—	0.6× / 1.6
Other · Caribbean Sea	1	3.5	1	3	5.0× / 0.2
Icebergs · Indian Ocean	1	3.5	0	—	new / 0
Nav aids · Beaufort Sea	1	3.4	1	32	1.3× / 0.8
Derelicts · Alboran Sea	1	3	0	—	new / 0
Derelicts · Arafura Sea	1	3	0	—	new / 0
Incidents · Banda Sea	1	3	0	—	2.5× / 0.4
Debris · Celtic Sea	1	3	0	—	1.7× / 0.6
Containers · Indian Ocean	1	3	0	—	new / 0
Icebergs · Kara Sea	1	3	0	—	0.7× / 1.4
Derelicts · North Atlantic Ocean	1	3	0	—	0.2× / 5.6
Debris · North Pacific Ocean	1	3	0	—	1.0× / 1
Derelicts · North Pacific Ocean	1	3	0	—	1.0× / 1
Derelicts · Philippine Sea	1	3	0	—	new / 0
Quakes · Sea of Okhotsk	1	3	0	—	2.5× / 0.4
Quakes · Solomon Sea	1	3	0	—	0.4× / 2.6
Quakes · South Atlantic Ocean	1	3	0	—	0.4× / 2.6
Quakes · Southern Ocean	1	3	0	—	2.5× / 0.4
Quakes · Tasman Sea	1	3	0	—	5.0× / 0.2
Derelicts · South Atlantic Ocean	1	2.9	0	—	0.7× / 1.4
Exercises · Gulf of Oman	1	2.8	0	—	new / 0
Nav aids · Tyrrhenian Sea	1	2.7	0	—	new / 0
Incidents · Gulf of Thailand	1	2	0	—	1.3× / 0.8
Cable ops · Mediterranean Sea - Eastern Basin	1	1.8	1	1	5.0× / 0.2
Exercises · English Channel	1	1.6	0	—	new / 0
Quakes · Banda Sea	1	1.5	1	1	0.6× / 1.8
Icebergs · North Atlantic Ocean	1	1.1	1	1	5.0× / 0.2
Icebergs · Barentsz Sea	1	1	0	—	5.0× / 0.2
Incidents · Bass Strait	1	0.9	0	—	5.0× / 0.2
Other · Celtic Sea	1	0.7	0	—	new / 0
Nav aids · Gulf of Alaska	1	0.4	0	—	1.7× / 0.6
Exercises · Davis Strait	1	0.3	0	—	new / 0
Wrecks · North Atlantic Oceanlong running	0	310	10	1,014	0.0× / 0.2
Wrecks · Arabian Sealong running	0	124	4	768	0.0× / 0.4
Wrecks · The Northwestern Passages	0	124	4	61	— / 0
Nav aids · Bay of Bengallong running	0	93.5	3	508	0.0× / 0.8
Surveys · Arctic Oceanlong running	0	93	3	377	0.0× / 0.6
Exercises · Ionian Sea	0	93	3	292	— / 0
Nav aids · Mozambique Channellong running	0	93	3	382	0.0× / 0.2
Wrecks · North Pacific Oceanlong running	0	93	3	941	0.0× / 0.6
Wrecks · Persian Gulf	0	93	3	359	— / 0
Other · Persian Gulflong running	0	78.7	2	482	— / 0
Ordnance · North Sealong running	0	67.7	2	748	0.0× / 0.6
Other · Arafura Sea	0	62	2	207	— / 0
Wrecks · Bay of Bengal	0	62	2	129	0.0× / 0.2
Surveys · Black Sea	0	62	2	235	0.0× / 2.8
Wrecks · English Channel	0	62	2	296	0.0× / 0.4
Surveys · Hudson Bay	0	62	2	74	— / 0
Wrecks · Inner Seas off the West Coast of Scotlandlong running	0	62	2	387	0.0× / 0.2
Nav aids · Mediterranean Sea - Eastern Basin	0	62	2	174	0.0× / 0.6
Other · North Atlantic Ocean	0	62	2	34	0.0× / 1
Restricted · South Atlantic Oceanlong running	0	62	2	668	0.0× / 0.8
Nav aids · Tasman Sea	0	62	2	247	0.0× / 1
Nav aids · Andaman or Burma Sea	0	56.6	1	300	— / 0
Nav aids · Laccadive Sea	0	43.9	1	74	0.0× / 1

Cite: seahazards.com Sea Ledger, 2021-10, 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.