Sea Ledger, October 2020

2020-10-01 to 2020-10-31 · archive

issued: 817
warning-days in force: 10,074
in force at month end: 291
sea × type cells: 246

baseline: same month, previous 5 years (2019-10, 2018-10, 2017-10, 2016-10, 2015-10)

By type

type	issued	warning-days	in force at end
Exercises	224	1,708.3	51
Incidents	115	927.8	20
Icebergs	98	112.7	4
Surveys	71	1,659.9	55
Nav aids	65	2,140.3	58
Missiles	55	444.9	11
Quakes	43	117.2	4
Cable ops	36	422.8	17
Derelicts	21	88.7	2
Other	19	412.3	10
Containers	16	20.5	3
Spills	13	215	5
Debris	10	53.7	2
Storms	9	18.7	1
Wrecks	8	1,369.8	38
Piracy	8	53.9	1
Structures	2	55	1
Ordnance	2	40.4	1
Mines	1	17.6	1
Restricted	1	101.6	3
Volcanic	0	93	3

By sea and type · 200 cells, most issued first

cell	issued	warning-days	at end	longest d	vs 5 y
Incidents · South China Sea	54	282.8	10	265	1.8× / 29.4
Exercises · North Pacific Oceansurge	41	185.2	6	37	2.2× / 18.4
Exercises · Black Seasurge	37	291.4	13	52	2.4× / 15.4
Icebergs · South Atlantic Ocean	31	30.9	1	31	1.2× / 25.6
Exercises · Mediterranean Sea - Eastern Basin	29	152.5	2	303	1.8× / 16.4
Icebergs · Southern Oceansurge	29	29	1	31	2.0× / 14.2
Icebergs · Labrador Sea	27	33	0	—	0.9× / 28.8
Exercises · Bay of Bengalsurge	20	95.2	3	40	2.0× / 9.8
Incidents · North Pacific Ocean	17	179.9	4	45	0.8× / 20.6
Quakes · South Pacific Ocean	17	49.5	1	30	1.6× / 10.8
Surveys · South Atlantic Ocean	14	159.9	6	43	0.9× / 15.4
Missiles · North Atlantic Oceansurge	14	27.9	2	33	2.8× / 5
Exercises · Arabian Sea	12	95.9	2	38	1.3× / 9.4
Exercises · South Pacific Oceansurge	12	57.4	3	32	2.2× / 5.4
Quakes · North Pacific Oceansurge	12	33.4	0	—	3.2× / 3.8
Exercises · Aegean Sea	11	208.6	7	306	1.1× / 9.8
Cable ops · North Atlantic Ocean	11	88.2	1	38	1.6× / 7
Missiles · Indian Oceansurge	11	26.7	1	33	55× / 0.2
Missiles · Black Sea	10	217.9	6	33	1.9× / 5.2
Surveys · Mediterranean Sea - Eastern Basin	10	133.4	5	133	1.6× / 6.2
Missiles · Barentsz Sea	10	79.8	0	—	1.2× / 8.2
Nav aids · South Pacific Oceansurgelong running	9	263.8	9	726	5.0× / 1.8
Storms · Gulf of Mexicosurge	9	18.7	1	22	3.5× / 2.6
Nav aids · North Atlantic Oceanlong running	8	152.6	4	448	1.1× / 7.2
Exercises · North Atlantic Ocean	8	77.1	3	93	0.7× / 11
Nav aids · Inner Seas off the West Coast of Scotland	8	70.9	2	324	1.7× / 4.8
Exercises · Yellow Sea	8	48.1	2	31	1.1× / 7.2
Cable ops · Aegean Seanew	8	37.7	4	55	new / 0
Derelicts · North Atlantic Ocean	8	24	0	—	1.4× / 5.6
Containers · Celtic Seasurge	8	7	0	—	20× / 0.4
Surveys · Persian Gulfsurgelong running	7	106.8	4	522	2.5× / 2.8
Surveys · North Atlantic Oceanlong running	6	299.1	10	1,080	0.9× / 6.8
Spills · Gulf of Mexico	6	102	3	38	0.6× / 9.4
Exercises · Mediterranean Sea - Western Basinsurge	6	83.3	3	303	10× / 0.6
Exercises · South Atlantic Ocean	6	80.1	1	58	0.6× / 10
Exercises · Japan Seasurge	6	49	0	—	30× / 0.2
Incidents · South Atlantic Ocean	6	20.3	0	—	1.1× / 5.6
Icebergs · Laptev Seasurge	6	13	0	—	4.3× / 1.4
Nav aids · South Atlantic Ocean	5	167.6	5	218	0.7× / 6.8
Surveys · Black Seasurge	5	75.3	4	136	2.5× / 2
Incidents · North Atlantic Oceanlong running	5	69.3	1	414	0.5× / 10.6
Incidents · South Pacific Ocean	5	48.2	0	—	0.6× / 8.8
Incidents · Indian Ocean	5	34.1	0	—	1.0× / 5.2
Surveys · Mediterranean Sea - Western Basinsurge	4	66	2	129	6.7× / 0.6
Exercises · Barentsz Sea	4	57.4	1	129	1.4× / 2.8
Surveys · Arabian Sea	4	57	3	57	0.9× / 4.2
Cable ops · South China Seasurge	4	48.7	3	108	5.0× / 0.8
Exercises · Gulf of Mexico	4	31.2	0	—	1.8× / 2.2
Missiles · South Pacific Oceansurge	4	28	0	—	3.3× / 1.2
Cable ops · Arabian Seasurge	4	27.3	2	20	10× / 0.4
Exercises · Indian Oceansurge	4	13.8	0	—	3.3× / 1.2
Debris · Arafura Seasurge	4	11.6	1	11	6.7× / 0.6
Other · Bering Seanew	4	8.1	0	—	new / 0
Icebergs · Davis Straitsurge	4	3.8	2	4	5.0× / 0.8
Nav aids · Caribbean Sea	3	405.8	5	281	1.3× / 2.4
Other · North Atlantic Oceansurge	3	50.7	1	108	7.5× / 0.4
Spills · North Pacific Ocean	3	42	1	37	1.7× / 1.8
Piracy · Gulf of Guinea	3	21	0	—	1.7× / 1.8
Surveys · Mozambique Channelsurge	3	20.4	0	—	7.5× / 0.4
Exercises · Andaman or Burma Seasurge	3	13.4	0	—	3.0× / 1
Exercises · Caribbean Seasurge	3	12.8	0	—	2.1× / 1.4
Debris · Timor Seasurge	3	9	0	—	3.8× / 0.8
Exercises · Persian Gulfnew	3	8.7	0	—	new / 0
Nav aids · Coral Sea	3	6.7	0	—	1.0× / 3
Derelicts · South Atlantic Ocean	3	6.1	1	12	1.7× / 1.8
Containers · Bristol Channelnew	3	5.1	1	5	new / 0
Nav aids · Strait of Gibraltarsurge	3	3.1	0	—	15× / 0.2
Nav aids · Mediterranean Sea - Western Basin	2	103.2	3	153	10× / 0.2
Nav aids · North Sea	2	96.7	2	50	0.2× / 8.8
Nav aids · Gulf of Mexico	2	91.6	3	282	0.5× / 4.4
Wrecks · South Atlantic Ocean	2	65	4	96	5.0× / 0.4
Nav aids · Arabian Sea	2	64.6	2	359	3.3× / 0.6
Incidents · Caribbean Sea	2	47.4	1	172	0.5× / 4.4
Surveys · Arctic Oceanlong running	2	43.8	2	387	5.0× / 0.4
Exercises · Laccadive Sea	2	35.4	1	33	0.8× / 2.4
Incidents · Mediterranean Sea - Western Basin	2	33.1	1	20	1.0× / 2
Spills · The Coastal Waters of Southeast Alaska and British Columbia	2	33	0	—	2.5× / 0.8
Surveys · Laccadive Sea	2	31.1	2	15	5.0× / 0.4
Surveys · Barentsz Sea	2	27.1	1	141	3.3× / 0.6
Surveys · Andaman or Burma Sea	2	26.1	1	26	3.3× / 0.6
Structures · South Atlantic Ocean	2	24	0	—	2.5× / 0.8
Incidents · Philippine Sea	2	23.4	0	—	0.3× / 6.4
Surveys · North Pacific Ocean	2	18.3	1	35	2.0× / 1
Piracy · North Atlantic Oceannew	2	14	0	—	new / 0
Other · South Atlantic Ocean	2	12.7	1	12	10× / 0.2
Nav aids · Davis Strait	2	12.6	0	—	1.7× / 1.2
Missiles · Japan Sea	2	12.5	1	17	10× / 0.2
Cable ops · Mediterranean Sea - Western Basin	2	11.4	1	14	10× / 0.2
Other · Kara Seanew	2	9.5	1	16	new / 0
Ordnance · North Pacific Ocean	2	9.4	0	—	10× / 0.2
Derelicts · Mediterranean Sea - Eastern Basin	2	8.2	0	—	2.0× / 1
Missiles · Arabian Sea	2	7.8	0	—	10× / 0.2
Nav aids · Kara Sea	2	6.9	0	—	10× / 0.2
Quakes · Indian Ocean	2	6	0	—	1.3× / 1.6
Quakes · Solomon Sea	2	6	0	—	0.9× / 2.2
Incidents · Coral Sea	2	5.5	1	12	0.6× / 3.6
Exercises · Coral Sea	2	5.1	0	—	3.3× / 0.6
Derelicts · English Channel	2	4.8	0	—	5.0× / 0.4
Quakes · North Atlantic Ocean	2	4.6	1	11	1.4× / 1.4
Incidents · Bismarck Sea	2	3.8	0	—	1.0× / 2
Quakes · Aegean Seanew	2	1.7	1	1	new / 0
Cable ops · Celtic Sea	2	1.3	0	—	3.3× / 0.6
Containers · North Sea	2	0.5	1	0	10× / 0.2
Nav aids · North Pacific Oceanlong running	1	219.1	6	456	0.2× / 5.8
Wrecks · Caribbean Sealong running	1	191.6	2	1,370	2.5× / 0.4
Surveys · Kara Sea	1	77.5	1	92	1.0× / 1
Wrecks · North Pacific Oceanlong running	1	76.2	1	1,233	2.5× / 0.4
Restricted · South Atlantic Ocean	1	70.6	2	303	1.7× / 0.6
Nav aids · Gulf of California	1	60	2	38	2.5× / 0.4
Surveys · South Pacific Oceanlong running	1	60	2	395	1.0× / 1
Other · North Pacific Ocean	1	59.3	1	88	0.2× / 6.2
Nav aids · Bay of Bengal	1	46.5	2	143	1.0× / 1
Nav aids · Laccadive Sealong running	1	36.4	2	547	1.3× / 0.8
Surveys · North Sea	1	36.2	1	71	0.6× / 1.8
Nav aids · Persian Gulf	1	35.3	2	199	new / 0
Nav aids · Mediterranean Sea - Eastern Basin	1	32	1	86	2.5× / 0.4
Nav aids · Great Australian Bight	1	31.4	1	40	0.3× / 3.6
Surveys · Bering Sealong running	1	31	1	419	new / 0
Wrecks · Inner Seas off the West Coast of Scotland	1	26.8	1	36	5.0× / 0.2
Other · English Channel	1	24.8	0	—	1.7× / 0.6
Spills · North Atlantic Ocean	1	24	1	34	0.4× / 2.4
Wrecks · Gulf of California	1	23.1	1	23	1.7× / 0.6
Nav aids · The Northwestern Passages	1	22.5	0	—	0.6× / 1.8
Incidents · Ionian Sea	1	18	0	—	5.0× / 0.2
Nav aids · Mozambique Channel	1	17.2	1	17	5.0× / 0.2
Wrecks · Mozambique Channel	1	17.2	1	17	new / 0
Cable ops · Caribbean Sea	1	16.8	1	31	1.3× / 0.8
Cable ops · Mediterranean Sea - Eastern Basin	1	16.5	0	—	5.0× / 0.2
Incidents · Ceram Sea	1	16.4	0	—	new / 0
Incidents · Japan Sea	1	14.4	0	—	2.5× / 0.4
Spills · Caribbean Sea	1	14	0	—	5.0× / 0.2
Incidents · Alboran Sea	1	13.9	0	—	new / 0
Incidents · Gulf of Mexico	1	13.7	0	—	0.5× / 2
Cable ops · Irish Sea and St. George's Channel	1	9.3	0	—	new / 0
Incidents · Timor Sea	1	8.7	0	—	0.8× / 1.2
Mines · English Channel	1	8.1	1	8	new / 0
Incidents · Molukka Sea	1	7.9	0	—	new / 0
Exercises · Gulf of California	1	7.6	0	—	1.7× / 0.6
Incidents · Mozambique Channel	1	7.4	1	7	2.5× / 0.4
Surveys · Caribbean Sea	1	7	0	—	0.5× / 2
Piracy · South China Sea	1	7	0	—	2.5× / 0.4
Piracy · South Pacific Ocean	1	7	0	—	new / 0
Missiles · Southern Ocean	1	6.9	0	—	1.7× / 0.6
Wrecks · Bay of Bengal	1	6.6	1	6	new / 0
Other · South China Sea	1	6.4	0	—	0.5× / 2.2
Surveys · Bay of Bengal	1	6	1	31	0.4× / 2.8
Surveys · Inner Seas off the West Coast of Scotland	1	5.7	0	—	1.7× / 0.6
Missiles · Laccadive Sea	1	4.9	0	—	1.0× / 1
Piracy · Singapore Strait	1	4.9	1	4	5.0× / 0.2
Other · The Coastal Waters of Southeast Alaska and British Columbia	1	4.6	0	—	new / 0
Surveys · Philippine Sea	1	4.5	1	4	5.0× / 0.2
Exercises · Gulf of Guinea	1	4.4	0	—	new / 0
Other · Hudson Bay	1	4.2	0	—	5.0× / 0.2
Nav aids · Irish Sea and St. George's Channel	1	3.7	0	—	0.4× / 2.8
Other · North Sea	1	3.4	1	3	1.7× / 0.6
Derelicts · Mediterranean Sea - Western Basin	1	3.1	0	—	1.0× / 1
Icebergs · Barentsz Sea	1	3	0	—	new / 0
Derelicts · Bay of Bengal	1	3	0	—	2.5× / 0.4
Quakes · Bering Sea	1	3	0	—	2.5× / 0.4
Derelicts · Coral Sea	1	3	0	—	1.7× / 0.6
Quakes · Coral Sea	1	3	0	—	1.0× / 1
Quakes · Gulf of Alaska	1	3	0	—	new / 0
Containers · Gulf of Mexico	1	3	0	—	new / 0
Derelicts · Java Sea	1	3	0	—	new / 0
Debris · North Pacific Ocean	1	3	0	—	1.0× / 1
Debris · Philippine Sea	1	3	0	—	new / 0
Quakes · Philippine Sea	1	3	0	—	0.4× / 2.6
Containers · South China Sea	1	3	0	—	2.5× / 0.4
Quakes · Southern Ocean	1	3	0	—	2.5× / 0.4
Other · Timor Sea	1	3	0	—	new / 0
Cable ops · English Channel	1	2.1	0	—	new / 0
Derelicts · South Pacific Ocean	1	2.1	0	—	0.5× / 2.2
Containers · North Pacific Ocean	1	1.9	1	1	new / 0
Nav aids · Red Sea	1	1.9	0	—	new / 0
Other · Indian Ocean	1	1.3	0	—	2.5× / 0.4
Exercises · Tyrrhenian Sea	1	1.2	1	1	5.0× / 0.2
Debris · North Atlantic Ocean	1	1.1	1	1	0.8× / 1.2
Quakes · Norwegian Sea	1	1	1	1	new / 0
Nav aids · Gulf of Alaska	1	0.8	0	—	1.7× / 0.6
Nav aids · Bering Sea	1	0.7	0	—	5.0× / 0.2
Nav aids · English Channel	1	0.7	0	—	0.3× / 3.2
Incidents · Black Sea	1	0.6	0	—	2.5× / 0.4
Derelicts · Indian Ocean	1	0.4	0	—	0.2× / 4.6
Incidents · English Channel	1	0.2	0	—	new / 0
Incidents · Solomon Sea	1	0.2	0	—	1.3× / 0.8
Cable ops · South Pacific Ocean	1	0.2	1	0	2.5× / 0.4
Incidents · Celtic Sea	1	0.1	0	—	5.0× / 0.2
Incidents · Tasman Sea	1	0	0	—	1.7× / 0.6
Wrecks · South China Sealong running	0	279	9	622	0.0× / 1.8
Wrecks · Persian Gulflong running	0	217	7	486	— / 0
Wrecks · Arabian Sealong running	0	146.8	3	403	0.0× / 0.4
Wrecks · North Atlantic Oceanlong running	0	146.6	4	1,094	0.0× / 0.2
Exercises · Ionian Sea	0	93	3	306	— / 0
Surveys · Sea of Okhotsk	0	93	3	208	0.0× / 1.6
Other · Caribbean Sea	0	67.8	0	—	0.0× / 0.2
Nav aids · Andaman or Burma Sealong running	0	62	2	520	— / 0
Other · South Pacific Ocean	0	62	2	226	0.0× / 0.2
Wrecks · South Pacific Ocean	0	62	2	275	0.0× / 1
Cable ops · North Pacific Ocean	0	60	1	60	0.0× / 1
Wrecks · Gulf of Mexico	0	45.2	0	—	0.0× / 0.4

Cite: seahazards.com Sea Ledger, 2020-10, 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.