Sea Ledger, February 2021

2021-02-01 to 2021-02-28 · archive

issued: 645
warning-days in force: 8,698
in force at month end: 329
sea × type cells: 208

baseline: same month, previous 5 years (2020-02, 2019-02, 2018-02, 2017-02, 2016-02)

By type

type	issued	warning-days	in force at end
Exercises	140	1,516.5	55
Incidents	102	973.9	37
Surveys	69	1,481.2	60
Icebergs	63	67.1	4
Missiles	62	417.6	13
Nav aids	56	1,658.2	64
Quakes	56	154.9	5
Cable ops	29	493.4	22
Derelicts	21	139.1	5
Spills	16	180	8
Other	12	228.8	7
Piracy	5	45.8	0
Debris	5	15	0
Ordnance	3	46.5	3
Wrecks	2	1,009.7	36
Towing	2	6	0
Restricted	1	96.4	4
Mines	1	56	2
Structures	0	28	1
Volcanic	0	84	3

By sea and type · 200 cells, most issued first

cell	issued	warning-days	at end	longest d	vs 5 y
Quakes · South Pacific Oceansurge	36	96.5	3	26	5.0× / 7.2
Icebergs · Labrador Sea	28	33.1	2	29	1.0× / 26.8
Icebergs · South Atlantic Oceansurge	28	27.6	1	28	2.0× / 13.8
Exercises · Black Seasurge	24	339.6	17	93	2.1× / 11.4
Incidents · South China Sea	22	226.3	9	328	0.8× / 27.8
Exercises · North Pacific Ocean	21	228.9	7	62	0.9× / 22
Surveys · South Atlantic Ocean	20	222.6	8	88	1.0× / 20.2
Missiles · Indian Oceansurge	19	38.4	2	29	32× / 0.6
Missiles · North Atlantic Oceansurge	17	36.7	2	28	3.3× / 5.2
Incidents · North Pacific Ocean	16	110.5	8	38	0.9× / 17.8
Incidents · North Atlantic Ocean	15	104.3	4	38	1.3× / 11.4
Incidents · South Pacific Oceansurge	15	100.5	4	21	2.7× / 5.6
Exercises · Mediterranean Sea - Eastern Basin	13	52.8	6	31	0.6× / 21.4
Nav aids · North Sea	12	107.1	2	154	0.9× / 13.6
Surveys · Arabian Sea	9	142.4	7	53	1.6× / 5.6
Exercises · Arabian Sea	9	90.7	3	34	1.2× / 7.6
Exercises · North Atlantic Ocean	9	48.1	2	25	1.3× / 7
Exercises · Philippine Sea	9	15.8	0	—	2.0× / 4.6
Missiles · Barentsz Seasurge	8	61.1	1	34	2.9× / 2.8
Missiles · Black Sea	7	182.4	6	30	1.5× / 4.8
Nav aids · South Atlantic Ocean	7	180.2	8	125	0.8× / 8.4
Surveys · Persian Gulfsurgelong running	7	103.8	4	508	2.9× / 2.4
Exercises · Mediterranean Sea - Western Basinsurge	7	42.1	2	24	2.2× / 3.2
Exercises · Yellow Sea	7	39.9	2	30	1.0× / 6.8
Quakes · Coral Seanew	7	18	1	12	new / 0
Icebergs · Southern Ocean	7	6.4	1	6	0.3× / 24
Spills · North Pacific Oceansurge	6	77	3	39	3.8× / 1.6
Cable ops · North Atlantic Oceansurge	6	55.2	2	54	3.3× / 1.8
Derelicts · North Atlantic Ocean	6	28.6	0	—	0.5× / 11.2
Nav aids · North Atlantic Oceanlong running	5	245.6	8	568	1.4× / 3.6
Surveys · North Atlantic Ocean	5	221	8	121	0.8× / 6
Exercises · Bay of Bengal	5	91.3	2	30	0.5× / 9.2
Incidents · Laccadive Seasurge	5	78.8	0	—	2.8× / 1.8
Cable ops · Caribbean Seasurge	5	56.6	3	93	6.3× / 0.8
Exercises · South Atlantic Ocean	5	48.7	1	31	0.7× / 7
Missiles · Japan Seasurge	5	41.7	1	23	2.8× / 1.8
Exercises · South Pacific Ocean	5	14	0	—	0.8× / 6.6
Derelicts · Mediterranean Sea - Eastern Basinsurge	5	13.8	2	11	8.3× / 0.6
Exercises · Aegean Sea	4	232.2	6	55	0.4× / 10.6
Nav aids · North Pacific Oceanlong running	4	88.5	4	576	1.7× / 2.4
Exercises · Japan Seasurge	4	58	1	24	4.0× / 1
Incidents · Mediterranean Sea - Eastern Basin	4	44.9	2	37	0.4× / 10.6
Spills · The Coastal Waters of Southeast Alaska and British Columbiasurge	4	42	2	21	2.0× / 2
Incidents · Caribbean Sea	4	40.7	3	31	0.9× / 4.2
Exercises · Andaman or Burma Seasurge	4	25	0	—	5.0× / 0.8
Incidents · Coral Sea	4	8.2	0	—	0.7× / 6
Nav aids · Caribbean Sea	3	243.2	9	139	1.0× / 3
Surveys · Mediterranean Sea - Eastern Basin	3	166.6	6	116	1.4× / 2.2
Cable ops · North Pacific Oceansurge	3	82.1	3	180	15× / 0.2
Surveys · South Pacific Oceansurgelong running	3	62.7	1	515	7.5× / 0.4
Surveys · Bay of Bengal	3	49.7	2	45	0.9× / 3.2
Exercises · Laccadive Sea	3	40.2	1	30	1.4× / 2.2
Piracy · Gulf of Guinea	3	26.8	0	—	0.7× / 4.4
Incidents · Philippine Sea	3	23.4	2	38	0.4× / 7.2
Surveys · Celtic Seasurge	3	11.8	1	44	15× / 0.2
Missiles · South Pacific Oceansurge	3	11.4	0	—	2.1× / 1.4
Nav aids · English Channel	3	9.5	1	52	1.7× / 1.8
Quakes · Indian Ocean	3	9.3	1	30	1.9× / 1.6
Incidents · Bay of Biscaynew	3	2.4	0	—	new / 0
Nav aids · South Pacific Oceanlong running	2	186	8	846	0.7× / 2.8
Nav aids · Mediterranean Sea - Western Basin	2	111.7	3	273	1.7× / 1.2
Exercises · Ionian Sea	2	92.3	4	47	2.5× / 0.8
Surveys · Indian Ocean	2	68.6	3	55	0.7× / 3
Incidents · South Atlantic Ocean	2	53	1	34	0.3× / 7.4
Cable ops · Persian Gulfnew	2	48	2	98	new / 0
Cable ops · Aegean Sea	2	32.1	1	117	10× / 0.2
Exercises · Sea of Okhotsknew	2	26	1	24	new / 0
Surveys · Mediterranean Sea - Western Basin	2	23.6	1	46	10× / 0.2
Cable ops · South Atlantic Ocean	2	21	0	—	5.0× / 0.4
Surveys · Tasman Sea	2	19	1	18	3.3× / 0.6
Surveys · Mozambique Channel	2	18.3	1	44	5.0× / 0.4
Surveys · Irish Sea and St. George's Channelnew	2	17.9	1	17	new / 0
Surveys · Aegean Sea	2	15.7	1	15	1.4× / 1.4
Piracy · South Atlantic Oceannew	2	14	0	—	new / 0
Missiles · North Pacific Ocean	2	13	0	—	0.5× / 3.8
Nav aids · Indian Ocean	2	9.5	0	—	1.1× / 1.8
Exercises · Indian Ocean	2	7.7	0	—	1.3× / 1.6
Quakes · North Pacific Ocean	2	7.1	0	—	0.7× / 2.8
Spills · North Atlantic Ocean	2	7	2	6	0.7× / 2.8
Derelicts · Caribbean Sea	2	6	0	—	1.0× / 2
Towing · Great Australian Bightnew	2	6	0	—	new / 0
Cable ops · Gulf of Guinea	2	6	1	9	10× / 0.2
Quakes · Philippine Sea	2	6	0	—	1.0× / 2
Quakes · Solomon Sea	2	6	0	—	3.3× / 0.6
Other · Bering Sea	2	5.3	1	5	10× / 0.2
Incidents · Bismarck Sea	2	4.5	0	—	0.7× / 2.8
Ordnance · North Pacific Ocean	2	4	1	26	3.3× / 0.6
Nav aids · Celtic Sea	2	3	0	—	0.9× / 2.2
Nav aids · The Coastal Waters of Southeast Alaska and British Columbia	2	2.6	0	—	1.7× / 1.2
Derelicts · Laccadive Sea	2	0.8	0	—	1.7× / 1.2
Wrecks · North Atlantic Oceanlong running	1	113.7	4	769	new / 0
Surveys · Black Sea	1	75.3	3	114	1.7× / 0.6
Cable ops · Arabian Sea	1	56	2	41	0.5× / 2
Ordnance · North Sealong running	1	42.5	2	503	0.6× / 1.8
Nav aids · Inner Seas off the West Coast of Scotlandlong running	1	35.1	1	444	0.3× / 3.4
Nav aids · Andaman or Burma Sea	1	32.3	2	55	5.0× / 0.2
Nav aids · Arabian Sea	1	29.5	2	55	1.0× / 1
Mines · English Channel	1	28	1	44	new / 0
Wrecks · Southern Ocean	1	28	1	48	new / 0
Other · English Channel	1	27.7	1	27	0.7× / 1.4
Incidents · Arabian Sea	1	25.3	1	40	0.2× / 4.4
Incidents · Ionian Sea	1	19.5	0	—	5.0× / 0.2
Incidents · Bay of Bengal	1	17.1	1	38	1.7× / 0.6
Incidents · Andaman or Burma Sea	1	16.3	1	40	new / 0
Other · Arabian Sea	1	15.8	1	15	5.0× / 0.2
Incidents · Gulf of Thailand	1	15.3	0	—	1.0× / 1
Spills · Gulf of Mexico	1	15	0	—	0.2× / 5.4
Spills · Gulf of Alaska	1	14	0	—	1.0× / 1
Spills · Mediterranean Sea - Eastern Basin	1	14	0	—	new / 0
Restricted · Black Sea	1	12.4	1	12	5.0× / 0.2
Nav aids · Coral Sea	1	12.4	0	—	0.7× / 1.4
Nav aids · Gulf of California	1	12.1	1	12	new / 0
Other · North Pacific Ocean	1	12	0	—	1.0× / 1
Cable ops · South China Sea	1	11.5	1	11	1.0× / 1
Cable ops · Strait of Gibraltar	1	11.3	1	11	2.5× / 0.4
Spills · Bering Sea	1	11	1	11	0.8× / 1.2
Cable ops · Singapore Strait	1	9.9	0	—	2.5× / 0.4
Other · Great Australian Bight	1	9.6	0	—	new / 0
Exercises · Barentsz Sea	1	8.6	0	—	2.5× / 0.4
Exercises · Gulf of Oman	1	5.6	0	—	5.0× / 0.2
Missiles · Laccadive Sea	1	4.9	0	—	1.0× / 1
Nav aids · Arafura Sea	1	4.6	1	4	1.3× / 0.8
Other · Mediterranean Sea - Western Basin	1	4.6	0	—	new / 0
Surveys · Andaman or Burma Sea	1	4.5	1	4	0.8× / 1.2
Surveys · Caribbean Sea	1	4.3	1	4	new / 0
Incidents · Arafura Sea	1	4.2	0	—	2.5× / 0.4
Debris · Arafura Sea	1	3	0	—	5.0× / 0.2
Quakes · Bismarck Sea	1	3	0	—	2.5× / 0.4
Quakes · Celebes Sea	1	3	0	—	5.0× / 0.2
Debris · Celtic Sea	1	3	0	—	0.5× / 2.2
Derelicts · Coral Sea	1	3	0	—	1.3× / 0.8
Exercises · Coral Sea	1	3	0	—	2.5× / 0.4
Debris · Indian Ocean	1	3	0	—	1.7× / 0.6
Derelicts · Indian Ocean	1	3	0	—	0.4× / 2.6
Quakes · Ionian Sea	1	3	0	—	new / 0
Debris · Mediterranean Sea - Eastern Basin	1	3	0	—	2.5× / 0.4
Debris · Mediterranean Sea - Western Basin	1	3	0	—	new / 0
Derelicts · Mediterranean Sea - Western Basin	1	3	0	—	1.0× / 1
Quakes · North Atlantic Ocean	1	3	0	—	1.7× / 0.6
Other · North Atlantic Ocean	1	3	0	—	0.7× / 1.4
Exercises · Persian Gulf	1	3	0	—	new / 0
Exercises · Red Sea	1	3	0	—	5.0× / 0.2
Derelicts · South Atlantic Ocean	1	3	0	—	0.4× / 2.6
Nav aids · Tasman Sea	1	2.8	1	2	0.3× / 3
Derelicts · Great Australian Bight	1	2.7	0	—	new / 0
Incidents · Molukka Sea	1	2.4	0	—	1.7× / 0.6
Other · Philippine Sea	1	2.4	0	—	5.0× / 0.2
Nav aids · Laccadive Sea	1	2.3	1	2	1.7× / 0.6
Other · Coral Sea	1	1.9	0	—	1.3× / 0.8
Nav aids · Timor Sea	1	1.7	0	—	2.5× / 0.4
Cable ops · Mediterranean Sea - Western Basin	1	1.6	1	1	0.6× / 1.6
Cable ops · South Pacific Ocean	1	1.6	1	1	1.0× / 1
Nav aids · Gulf of Alaska	1	1.5	0	—	0.7× / 1.4
Other · Caribbean Sea	1	1.2	0	—	1.0× / 1
Surveys · Ligurian Sea	1	0.9	1	0	new / 0
Cable ops · Sea of Marmara	1	0.9	1	0	new / 0
Nav aids · Irish Sea and St. George's Channel	1	0.8	0	—	1.3× / 0.8
Derelicts · Arafura Sea	1	0.6	1	0	new / 0
Nav aids · Strait of Gibraltar	1	0.2	0	—	5.0× / 0.2
Other · South China Sea	1	0	0	—	1.3× / 0.8
Wrecks · Persian Gulflong running	0	252	9	606	— / 0
Wrecks · South China Sealong running	0	252	9	742	0.0× / 1.2
Nav aids · Persian Gulf	0	84	3	319	0.0× / 0.4
Wrecks · South Atlantic Ocean	0	84	3	216	0.0× / 1
Derelicts · Arabian Sealong running	0	74.5	2	401	0.0× / 0.4
Wrecks · Arabian Sealong running	0	56	2	523	0.0× / 1.2
Surveys · Arctic Ocean	0	56	2	132	— / 0
Surveys · Barentsz Sea	0	56	2	44	— / 0
Surveys · Bass Strait	0	56	2	32	0.0× / 1.2
Nav aids · Gulf of Mexico	0	56	2	85	0.0× / 3
Wrecks · Inner Seas off the West Coast of Scotland	0	56	2	142	0.0× / 0.2
Nav aids · Mozambique Channel	0	56	2	137	0.0× / 0.2
Wrecks · North Pacific Oceanlong running	0	56	2	696	— / 0
Other · Persian Gulf	0	56	2	237	0.0× / 0.2
Volcanic · Philippine Sea	0	56	2	72	0.0× / 0.4
Restricted · South Atlantic Oceanlong running	0	56	2	423	0.0× / 0.4
Other · Gulf of Mexico	0	46.4	1	48	0.0× / 0.4
Incidents · Java Sea	0	39.6	1	356	0.0× / 1.2
Missiles · Aegean Sea	0	28	1	47	— / 0
Nav aids · Alboran Sea	0	28	1	157	— / 0
Nav aids · Bay of Bengal	0	28	1	263	0.0× / 1
Surveys · Bering Sea	0	28	1	130	— / 0
Cable ops · Black Sea	0	28	1	33	— / 0
Wrecks · English Channel	0	28	1	51	0.0× / 0.4
Nav aids · Gulf of Thailandlong running	0	28	1	500	— / 0
Cable ops · Indian Ocean	0	28	1	64	0.0× / 0.6
Wrecks · Japan Sea	0	28	1	38	— / 0
Cable ops · Mediterranean Sea - Eastern Basin	0	28	1	88	0.0× / 2.2
Nav aids · Mediterranean Sea - Eastern Basin	0	28	1	206	— / 0
Other · Mediterranean Sea - Eastern Basin	0	28	1	157	0.0× / 0.8
Volcanic · Mozambique Channellong running	0	28	1	514	— / 0
Wrecks · Mozambique Channel	0	28	1	137	— / 0
Nav aids · Norwegian Sea	0	28	1	30	0.0× / 0.4
Mines · Persian Gulf	0	28	1	56	— / 0
Restricted · Persian Gulflong running	0	28	1	683	0.0× / 0.2
Wrecks · Red Sealong running	0	28	1	442	— / 0
Structures · South China Sealong running	0	28	1	461	— / 0
Surveys · South China Sealong running	0	28	1	535	0.0× / 0.6
Surveys · Tyrrhenian Sea	0	28	1	28	0.0× / 0.4
Incidents · Gulf of Mexico	0	27.7	0	—	0.0× / 3

Cite: seahazards.com Sea Ledger, 2021-02, 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.