Sea Ledger, December 2021

2021-12-01 to 2021-12-31 · archive

issued: 642
warning-days in force: 12,231
in force at month end: 370
sea × type cells: 242

baseline: same month, previous 5 years (2020-12, 2019-12, 2018-12, 2017-12, 2016-12)

By type

type	issued	warning-days	in force at end
Incidents	103	976.9	22
Exercises	103	1,321.7	22
Icebergs	97	111.3	4
Surveys	67	2,116.6	75
Nav aids	57	3,313.3	108
Quakes	48	148.2	5
Missiles	38	335.3	5
Derelicts	30	296.6	10
Other	24	587.7	25
Cable ops	22	396.1	13
Debris	15	45.5	0
Towing	15	16.3	1
Spills	11	196	2
Wrecks	6	1,728.3	58
Piracy	4	22.5	2
Containers	1	3	0
Mines	1	36.8	1
Volcanic	0	369.6	11
Structures	0	62	2
Restricted	0	62	2
Ordnance	0	84.8	2

By sea and type · 200 cells, most issued first

cell	issued	warning-days	at end	longest d	vs 5 y
Icebergs · Southern Oceansurge	58	58.4	1	31	3.2× / 18
Icebergs · Labrador Sea	32	36.6	2	32	1.0× / 31.2
Incidents · South China Sealong running	30	238.2	6	634	0.7× / 40.8
Surveys · North Atlantic Oceansurgelong running	24	476.5	32	365	4.1× / 5.8
Exercises · Arabian Seasurge	20	132.9	3	36	2.0× / 9.8
Exercises · Bay of Bengal	19	128.4	1	46	1.6× / 12
Nav aids · North Sea	16	288.8	11	127	1.8× / 8.8
Exercises · North Pacific Ocean	16	199.6	7	35	1.1× / 14.2
Incidents · North Pacific Ocean	16	188	1	43	0.9× / 17.6
Towing · North Pacific Oceannew	15	16.3	1	16	new / 0
Surveys · South Atlantic Ocean	12	149.6	2	38	0.9× / 13.8
Missiles · North Atlantic Ocean	11	98.6	3	35	1.9× / 5.8
Quakes · South Pacific Ocean	11	33	0	—	1.0× / 10.8
Exercises · Black Sea	10	281.6	4	123	0.8× / 12.6
Incidents · Arabian Seasurge	10	115.2	0	—	4.2× / 2.4
Exercises · South Atlantic Ocean	9	83.3	0	—	1.2× / 7.4
Incidents · North Atlantic Ocean	9	57.3	4	15	0.8× / 12
Exercises · South Pacific Ocean	9	52	0	—	1.3× / 7.2
Quakes · North Pacific Ocean	9	30.8	0	—	1.0× / 9
Cable ops · North Atlantic Oceansurge	8	95.5	4	77	3.3× / 2.4
Surveys · Persian Gulfsurge	7	263.9	8	347	2.1× / 3.4
Spills · North Pacific Oceansurge	7	107	2	41	3.5× / 2
Other · Tasman Seasurge	7	18.7	0	—	12× / 0.6
Derelicts · North Atlantic Ocean	7	17.7	0	—	1.2× / 6
Missiles · Barentsz Sea	6	41.2	0	—	0.9× / 6.8
Missiles · South Pacific Ocean	6	29.4	0	—	1.1× / 5.2
Quakes · Banda Seasurge	6	17.2	1	17	7.5× / 0.8
Quakes · South Atlantic Oceansurge	6	16.8	1	27	6.0× / 1
Nav aids · North Atlantic Oceanlong running	5	319	10	693	0.8× / 6.6
Cable ops · North Pacific Oceannew	5	98.4	4	288	new / 0
Other · North Atlantic Oceansurge	5	64.6	5	95	3.1× / 1.6
Exercises · North Atlantic Ocean	5	60.4	2	127	0.7× / 7
Derelicts · Mediterranean Sea - Eastern Basinsurge	5	8	0	—	25× / 0.2
Nav aids · South Pacific Oceanlong running	4	273.5	11	480	1.3× / 3
Nav aids · Mediterranean Sea - Western Basinsurgelong running	4	203.6	5	539	10× / 0.4
Surveys · Caribbean Seasurge	4	64.7	2	37	20× / 0.2
Derelicts · South Pacific Ocean	4	58.4	2	37	1.3× / 3.2
Surveys · Tasman Seasurge	4	56.8	1	32	5.0× / 0.8
Surveys · Bay of Bengal	4	52.4	2	36	1.5× / 2.6
Missiles · Japan Seasurge	4	46.4	0	—	3.3× / 1.2
Incidents · Indian Ocean	4	15.6	1	35	0.9× / 4.4
Incidents · Coral Sea	4	15.4	0	—	0.9× / 4.2
Debris · North Atlantic Ocean	4	12	0	—	0.9× / 4.2
Icebergs · South Atlantic Ocean	4	5.4	1	3	0.1× / 31.2
Nav aids · Caribbean Sealong running	3	431.4	15	445	0.8× / 3.8
Nav aids · South Atlantic Ocean	3	263.4	9	148	0.7× / 4.4
Surveys · Arabian Sea	3	134.3	4	59	0.5× / 5.6
Incidents · Laccadive Sea	3	66.5	2	50	0.9× / 3.2
Incidents · Gulf of Thailand	3	48.2	0	—	1.5× / 2
Missiles · North Pacific Ocean	3	45.5	1	199	0.7× / 4.6
Exercises · Laccadive Sea	3	44.8	1	33	1.5× / 2
Nav aids · English Channel	3	40.3	1	126	1.5× / 2
Incidents · South Pacific Ocean	3	36	0	—	0.5× / 5.8
Other · Great Australian Bightsurge	3	32.6	3	11	15× / 0.2
Derelicts · South China Sea	3	31.7	1	137	0.8× / 3.8
Nav aids · Coral Sea	3	27.8	1	197	0.7× / 4.2
Incidents · Arafura Seasurge	3	17.7	1	30	15× / 0.2
Derelicts · Indian Ocean	3	16.3	2	39	0.8× / 3.8
Missiles · South Atlantic Oceansurge	3	16.3	0	—	2.5× / 1.2
Incidents · Caribbean Sea	3	14.2	3	11	0.9× / 3.2
Nav aids · Inner Seas off the West Coast of Scotland	3	14	1	24	0.9× / 3.2
Incidents · Mediterranean Sea - Eastern Basin	3	12.8	2	7	0.2× / 14.6
Icebergs · Indian Oceansurge	3	10.9	0	—	15× / 0.2
Quakes · Southern Oceansurge	3	9	0	—	15× / 0.2
Other · North Seasurge	3	8.9	2	5	3.8× / 0.8
Exercises · Indian Ocean	3	4.6	0	—	1.9× / 1.6
Wrecks · Arabian Sealong running	2	157.7	6	829	3.3× / 0.6
Derelicts · Arabian Sea	2	49.3	1	196	1.0× / 2
Exercises · Mediterranean Sea - Eastern Basin	2	47.1	1	196	0.1× / 18.4
Spills · The Coastal Waters of Southeast Alaska and British Columbia	2	38	0	—	2.0× / 1
Other · North Pacific Ocean	2	34	2	273	0.3× / 7.4
Incidents · South Atlantic Ocean	2	31.3	0	—	0.2× / 9.2
Nav aids · Great Australian Bight	2	26.7	1	26	1.1× / 1.8
Incidents · Bay of Bengal	2	23.1	0	—	2.5× / 0.8
Cable ops · Philippine Sea	2	23.1	0	—	2.0× / 1
Cable ops · Irish Sea and St. George's Channel	2	16.5	0	—	3.3× / 0.6
Exercises · Red Sea	2	14	0	—	5.0× / 0.4
Cable ops · Arabian Sea	2	9.3	0	—	3.3× / 0.6
Piracy · Gulf of Guinea	2	8.5	1	18	0.4× / 5.6
Nav aids · Gulf of Alaska	2	7.9	0	—	3.3× / 0.6
Incidents · Bismarck Sea	2	6	0	—	0.9× / 2.2
Quakes · Eastern China Seanew	2	6	0	—	new / 0
Quakes · Indian Ocean	2	6	0	—	1.1× / 1.8
Exercises · Mediterranean Sea - Western Basin	2	6	0	—	3.3× / 0.6
Derelicts · Mozambique Channel	2	6	0	—	10× / 0.2
Quakes · Philippine Sea	2	6	0	—	0.9× / 2.2
Debris · South Atlantic Ocean	2	6	0	—	2.0× / 1
Debris · South China Seanew	2	6	0	—	new / 0
Quakes · Mediterranean Sea - Eastern Basinnew	2	5.8	1	5	new / 0
Nav aids · North Pacific Oceanlong running	1	282	10	391	0.1× / 7.2
Surveys · Mediterranean Sea - Eastern Basin	1	130.1	4	133	0.2× / 4.8
Nav aids · Arabian Sea	1	127.1	4	193	1.0× / 1
Nav aids · Indian Ocean	1	109	3	265	0.8× / 1.2
Wrecks · Persian Gulflong running	1	97.3	4	420	1.3× / 0.8
Surveys · Indian Ocean	1	74.9	1	318	0.4× / 2.6
Surveys · South China Sealong running	1	62	2	841	1.7× / 0.6
Surveys · South Pacific Oceanlong running	1	55	1	821	1.7× / 0.6
Surveys · Andaman or Burma Sea	1	53	1	32	1.3× / 0.8
Derelicts · Bay of Bengal	1	36.8	2	108	0.8× / 1.2
Surveys · Barentsz Sea	1	32.1	0	—	2.5× / 0.4
Surveys · Red Sea	1	27.3	1	27	5.0× / 0.2
Wrecks · Singapore Strait	1	26.5	1	26	new / 0
Nav aids · Alboran Sea	1	23.2	1	23	new / 0
Wrecks · North Sea	1	20.7	1	20	2.5× / 0.4
Other · South China Sea	1	18.4	0	—	1.3× / 0.8
Incidents · Andaman or Burma Sea	1	17.2	0	—	2.5× / 0.4
Surveys · Laccadive Sea	1	17.1	1	17	2.5× / 0.4
Nav aids · Arafura Sea	1	17	0	—	2.5× / 0.4
Spills · North Atlantic Ocean	1	16	0	—	0.6× / 1.8
Spills · Chukchi Sea	1	14	0	—	new / 0
Cable ops · Strait of Gibraltar	1	11.6	0	—	2.5× / 0.4
Surveys · Adriatic Sea	1	10.6	1	10	new / 0
Incidents · Gulf of Mexico	1	10.6	1	10	0.5× / 2
Cable ops · Sea of Marmara	1	9.6	1	9	2.5× / 0.4
Missiles · Black Sea	1	9.2	0	—	0.5× / 2
Exercises · Coral Sea	1	8.6	0	—	5.0× / 0.2
Incidents · Philippine Sea	1	8	0	—	0.5× / 2.2
Exercises · Mozambique Channel	1	7.6	0	—	new / 0
Cable ops · Tasman Sea	1	7.6	0	—	0.6× / 1.8
Missiles · Indian Ocean	1	7.3	0	—	0.3× / 3.2
Piracy · Gulf of Aden	1	7	0	—	new / 0
Piracy · South Pacific Ocean	1	7	1	6	new / 0
Mines · Laccadive Sea	1	5.8	0	—	new / 0
Missiles · Arctic Ocean	1	5	0	—	1.3× / 0.8
Exercises · Andaman or Burma Sea	1	4.1	0	—	1.0× / 1
Missiles · Laccadive Sea	1	3.8	0	—	1.3× / 0.8
Nav aids · Davis Strait	1	3.5	0	—	1.7× / 0.6
Debris · Indian Ocean	1	3.5	0	—	1.7× / 0.6
Debris · Arafura Sea	1	3	0	—	0.6× / 1.6
Derelicts · Bass Strait	1	3	0	—	5.0× / 0.2
Containers · Celtic Sea	1	3	0	—	1.0× / 1
Other · Coral Sea	1	3	0	—	2.5× / 0.4
Quakes · Gulf of Alaska	1	3	0	—	new / 0
Debris · Laccadive Sea	1	3	0	—	new / 0
Derelicts · Makassar Strait	1	3	0	—	new / 0
Debris · Mediterranean Sea - Western Basin	1	3	0	—	new / 0
Debris · North Pacific Ocean	1	3	0	—	1.3× / 0.8
Quakes · Solomon Sea	1	3	0	—	0.2× / 5.6
Debris · South Pacific Ocean	1	3	0	—	1.7× / 0.6
Debris · Timor Sea	1	3	0	—	1.7× / 0.6
Derelicts · Timor Sea	1	3	0	—	0.8× / 1.2
Other · Timor Sea	1	3	0	—	5.0× / 0.2
Quakes · Bering Sea	1	2.8	1	2	new / 0
Nav aids · Celtic Sea	1	1.9	0	—	0.4× / 2.4
Incidents · Malacca Strait	1	1.6	0	—	1.7× / 0.6
Quakes · Molukka Sea	1	1.4	1	1	1.7× / 0.6
Missiles · Philippine Sea	1	1.1	0	—	1.7× / 0.6
Nav aids · Strait of Gibraltar	1	1	0	—	1.7× / 0.6
Nav aids · Bay of Biscay	1	0.8	0	—	new / 0
Incidents · Great Australian Bight	1	0.5	0	—	1.0× / 1
Other · Gulf of Alaska	1	0.5	0	—	5.0× / 0.2
Wrecks · Indian Ocean	1	0.1	0	—	new / 0
Incidents · Tasman Sea	1	0.1	0	—	0.4× / 2.6
Quakes · Flores Sea	1	0	0	—	new / 0
Wrecks · North Atlantic Oceanlong running	0	310	10	1,075	0.0× / 0.2
Volcanic · Philippine Sealong running	0	279	9	378	0.0× / 0.8
Nav aids · Gulf of Mexicolong running	0	248	8	391	0.0× / 2.2
Wrecks · South China Sealong running	0	248	8	1,048	0.0× / 1.2
Wrecks · South Atlantic Ocean	0	155	5	347	0.0× / 0.8
Wrecks · Bay of Bengal	0	124	4	190	— / 0
Wrecks · The Northwestern Passages	0	124	4	122	0.0× / 0.2
Wrecks · Laccadive Sea	0	93	3	226	0.0× / 0.4
Nav aids · Mozambique Channellong running	0	93	3	443	— / 0
Wrecks · North Pacific Oceanlong running	0	93	3	1,002	0.0× / 0.4
Exercises · Aegean Sea	0	92.2	1	353	0.0× / 13.4
Exercises · Ionian Sea	0	91.5	0	—	0.0× / 1.8
Ordnance · North Sealong running	0	84.8	2	809	0.0× / 0.8
Nav aids · Andaman or Burma Sea	0	62	2	361	0.0× / 0.6
Other · Arafura Sea	0	62	2	268	0.0× / 0.2
Surveys · Arctic Oceanlong running	0	62	2	438	— / 0
Wrecks · Caribbean Sea	0	62	2	283	0.0× / 0.4
Wrecks · English Channel	0	62	2	357	0.0× / 0.8
Surveys · Hudson Bay	0	62	2	135	— / 0
Wrecks · Inner Seas off the West Coast of Scotlandlong running	0	62	2	448	— / 0
Nav aids · Mediterranean Sea - Eastern Basin	0	62	2	235	0.0× / 0.2
Other · Persian Gulflong running	0	62	2	543	0.0× / 0.2
Structures · South Atlantic Ocean	0	62	2	211	0.0× / 1
Surveys · The Northwestern Passages	0	62	2	107	— / 0
Nav aids · Bay of Bengallong running	0	59.4	1	569	0.0× / 0.6
Nav aids · Southern Ocean	0	45.6	1	50	— / 0
Surveys · Black Sea	0	38.5	1	296	0.0× / 2
Missiles · Aegean Sea	0	31	1	353	0.0× / 0.8
Other · Arabian Sea	0	31	1	113	0.0× / 0.2
Surveys · Baffin Bay	0	31	1	143	— / 0
Nav aids · Balearic (Iberian Sea)	0	31	1	68	— / 0
Nav aids · Barentsz Sea	0	31	1	95	— / 0
Cable ops · Bay of Bengal	0	31	1	35	0.0× / 0.2
Surveys · Bay of Biscay	0	31	1	179	0.0× / 0.4
Other · Bering Sea	0	31	1	92	0.0× / 0.4
Surveys · Bering Sea	0	31	1	168	— / 0
Cable ops · Black Sea	0	31	1	339	0.0× / 0.2
Nav aids · Black Sea	0	31	1	260	0.0× / 0.6
Derelicts · Caribbean Sea	0	31	1	276	0.0× / 1.8
Exercises · Caribbean Sea	0	31	1	32	0.0× / 0.4
Other · Caribbean Sea	0	31	1	64	0.0× / 0.6
Volcanic · Caribbean Sea	0	31	1	263	— / 0
Surveys · Davis Strait	0	31	1	149	— / 0
Other · English Channel	0	31	1	97	0.0× / 0.4
Nav aids · Gulf of California	0	31	1	318	— / 0
Other · Gulf of Mexico	0	31	1	47	0.0× / 0.8

Cite: seahazards.com Sea Ledger, 2021-12, 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.