Sea Ledger, June 2021

2021-06-01 to 2021-06-30 · archive

issued: 588
warning-days in force: 10,158
in force at month end: 341
sea × type cells: 206

baseline: same month, previous 5 years (2020-06, 2019-06, 2018-06, 2017-06, 2016-06)

By type

type	issued	warning-days	in force at end
Exercises	140	1,420.3	50
Icebergs	92	105.3	5
Incidents	70	659.4	23
Surveys	66	1,607.3	50
Nav aids	62	2,859.8	99
Missiles	37	330.2	13
Cable ops	23	432.5	13
Quakes	22	67.9	0
Derelicts	22	204	7
Spills	16	204	7
Wrecks	15	1,427.7	48
Other	12	401.3	13
Structures	5	96.9	3
Piracy	3	21	0
Containers	2	7.4	0
Ordnance	1	72.8	2
Restricted	0	90	3
Volcanic	0	120	4
Mines	0	30	1

By sea and type · 200 cells, most issued first

cell	issued	warning-days	at end	longest d	vs 5 y
Exercises · North Pacific Ocean	31	322.6	14	65	1.3× / 24.2
Icebergs · Labrador Sea	30	35.9	2	31	1.6× / 18.6
Icebergs · Southern Ocean	30	30	1	30	1.7× / 17.8
Icebergs · South Atlantic Ocean	27	26.9	1	30	1.1× / 25
Incidents · South China Sealong running	15	177.9	6	450	0.7× / 23
Surveys · South Atlantic Ocean	15	174.5	4	78	0.9× / 16.6
Exercises · Black Sea	15	135.5	8	126	1.3× / 11.8
Surveys · North Seasurge	13	98.9	3	37	2.3× / 5.6
Nav aids · North Sea	12	197	5	148	1.4× / 8.4
Incidents · North Pacific Ocean	12	121.3	3	30	0.6× / 20.2
Exercises · South Pacific Oceansurge	12	62.6	3	34	2.5× / 4.8
Exercises · North Atlantic Ocean	11	127.9	3	96	1.6× / 6.8
Exercises · Bay of Bengal	11	85.1	2	33	1.8× / 6
Exercises · Indian Oceansurge	11	28.8	0	—	11× / 1
Surveys · North Atlantic Ocean	8	364.4	13	181	0.9× / 8.6
Missiles · Black Sea	8	168.4	7	31	1.5× / 5.2
Cable ops · North Atlantic Ocean	8	102.4	3	57	1.7× / 4.8
Quakes · South Pacific Ocean	8	25.9	0	—	0.7× / 12
Spills · Gulf of Mexico	7	67	4	23	0.7× / 9.8
Exercises · Arabian Sea	7	64.2	2	33	1.5× / 4.8
Exercises · Barentsz Seasurge	7	39.2	2	29	3.2× / 2.2
Missiles · Barentsz Sea	7	31.5	0	—	1.5× / 4.8
Exercises · Philippine Sea	7	26.3	1	22	0.8× / 8.8
Incidents · Coral Seasurge	7	22.2	0	—	2.1× / 3.4
Nav aids · North Atlantic Oceanlong running	6	331.4	12	690	1.1× / 5.6
Exercises · Sea of Okhotsksurge	6	61.9	0	—	30× / 0.2
Incidents · South Pacific Ocean	6	52.3	2	42	1.0× / 6.2
Missiles · North Atlantic Ocean	6	28.1	0	—	0.6× / 9.4
Incidents · South Atlantic Ocean	6	23.3	1	37	0.7× / 8.8
Derelicts · Indian Oceansurge	6	13.1	0	—	3.3× / 1.8
Nav aids · South Atlantic Ocean	5	337.2	13	168	0.6× / 8
Nav aids · Indian Oceansurge	5	76.7	4	81	2.8× / 1.8
Structures · South Atlantic Oceansurge	5	66.9	2	27	25× / 0.2
Surveys · Gulf of Mexicosurge	5	30	1	35	5.0× / 1
Missiles · Indian Oceansurge	5	25.2	0	—	2.1× / 2.4
Nav aids · South Pacific Oceanlong running	4	226.7	8	968	0.7× / 5.8
Nav aids · Arabian Seasurge	4	151.9	6	177	3.3× / 1.2
Surveys · Persian Gulf	4	116.3	4	163	1.7× / 2.4
Cable ops · North Pacific Oceansurge	4	87.1	2	111	6.7× / 0.6
Spills · North Atlantic Ocean	4	79	0	—	1.3× / 3.2
Nav aids · Coral Sea	4	64	3	61	0.8× / 5.2
Cable ops · Indian Oceansurge	4	51.2	3	37	4.0× / 1
Surveys · Sea of Okhotsk	4	48.4	3	27	0.9× / 4.2
Exercises · South Atlantic Ocean	4	38	1	32	0.5× / 8
Incidents · Indian Ocean	4	25.6	0	—	0.6× / 6.4
Missiles · North Pacific Ocean	4	25	2	15	0.8× / 5
Quakes · North Pacific Ocean	4	12	0	—	0.9× / 4.4
Wrecks · Arabian Seasurgelong running	3	109.6	3	645	15× / 0.2
Surveys · Mediterranean Sea - Eastern Basin	3	68.4	2	184	0.8× / 3.8
Incidents · Laccadive Seasurge	3	50.5	1	46	3.0× / 1
Piracy · Gulf of Guineasurge	3	21	0	—	3.8× / 0.8
Exercises · Japan Seasurge	3	16.4	1	27	2.1× / 1.4
Cable ops · South Pacific Oceansurge	3	15.3	1	8	5.0× / 0.6
Exercises · Andaman or Burma Seasurge	3	14.4	0	—	5.0× / 0.6
Incidents · Bay of Bengalsurge	3	11.5	2	6	3.0× / 1
Nav aids · Bass Straitsurge	3	10.1	1	19	5.0× / 0.6
Derelicts · North Pacific Ocean	3	9.6	0	—	1.5× / 2
Incidents · Bismarck Seasurge	3	6.6	1	14	3.0× / 1
Nav aids · North Pacific Oceanlong running	2	228.4	7	698	0.6× / 3.6
Wrecks · North Pacific Oceanlong running	2	96	3	818	10× / 0.2
Nav aids · Mediterranean Sea - Western Basinlong running	2	95.1	4	395	10× / 0.2
Derelicts · Arabian Sealong running	2	70.7	2	523	1.1× / 1.8
Surveys · South Pacific Oceanlong running	2	70.5	3	637	5.0× / 0.4
Nav aids · Inner Seas off the West Coast of Scotlandlong running	2	61.2	1	566	0.9× / 2.2
Wrecks · Laccadive Sea	2	57.5	2	42	10× / 0.2
Surveys · Norwegian Sea	2	54.1	2	64	0.9× / 2.2
Nav aids · Celtic Sea	2	43	1	26	1.4× / 1.4
Wrecks · South Pacific Ocean	2	39.7	2	91	10× / 0.2
Other · North Pacific Ocean	2	36.9	1	89	0.8× / 2.6
Incidents · Gulf of Mexico	2	32.3	2	16	0.7× / 2.8
Nav aids · English Channel	2	30.8	1	63	2.5× / 0.8
Surveys · Mediterranean Sea - Western Basin	2	28.9	1	22	3.3× / 0.6
Incidents · Arabian Sea	2	27.2	0	—	0.6× / 3.2
Nav aids · Sea of Okhotsk	2	20.6	1	19	5.0× / 0.4
Derelicts · South Atlantic Ocean	2	20.5	1	32	1.3× / 1.6
Nav aids · Great Australian Bight	2	15.7	1	29	2.5× / 0.8
Exercises · Mediterranean Sea - Eastern Basin	2	13.9	1	14	0.1× / 14.6
Other · Sea of Okhotsknew	2	10.2	0	—	new / 0
Missiles · South Pacific Ocean	2	8.2	1	22	1.0× / 2
Wrecks · Bay of Bengalnew	2	7.4	1	7	new / 0
Exercises · Caribbean Sea	2	7.1	0	—	1.4× / 1.4
Exercises · Red Sea	2	6.6	0	—	5.0× / 0.4
Quakes · Banda Sea	2	6	0	—	2.0× / 1
Icebergs · Laptev Sea	2	6	0	—	2.0× / 1
Quakes · Molukka Sea	2	6	0	—	3.3× / 0.6
Derelicts · North Atlantic Ocean	2	5.3	1	7	0.6× / 3.6
Derelicts · Coral Sea	2	4.4	0	—	2.5× / 0.8
Icebergs · Kara Sea	2	3.5	1	3	1.0× / 2
Incidents · Timor Sea	2	0.2	0	—	10× / 0.2
Wrecks · North Atlantic Oceanlong running	1	285.8	9	891	2.5× / 0.4
Surveys · Indian Ocean	1	90	3	134	1.0× / 1
Nav aids · Bay of Bengallong running	1	89.6	3	385	1.0× / 1
Surveys · Black Sea	1	84.1	2	112	0.4× / 2.6
Nav aids · Mediterranean Sea - Eastern Basin	1	60	2	328	5.0× / 0.2
Wrecks · English Channel	1	42.2	2	173	2.5× / 0.4
Derelicts · Caribbean Sea	1	40.1	2	92	0.8× / 1.2
Other · Arabian Sea	1	35.5	1	43	0.8× / 1.2
Incidents · Java Sealong running	1	33.5	2	478	0.5× / 2
Derelicts · South Pacific Ocean	1	32.8	1	34	0.7× / 1.4
Nav aids · Arafura Sea	1	29.4	1	29	5.0× / 0.2
Exercises · Laccadive Sea	1	27.1	0	—	0.7× / 1.4
Cable ops · South China Sea	1	26	0	—	0.7× / 1.4
Surveys · Gulf of Guinea	1	25.8	1	25	2.5× / 0.4
Incidents · North Atlantic Ocean	1	25	1	37	0.1× / 13.8
Wrecks · Gulf of Suez	1	22.3	1	22	new / 0
Surveys · Celtic Sea	1	21.3	0	—	0.7× / 1.4
Wrecks · North Sea	1	17.2	0	—	0.7× / 1.4
Exercises · Bering Sea	1	16.7	0	—	1.7× / 0.6
Other · North Atlantic Ocean	1	15.9	1	15	0.5× / 2.2
Incidents · Philippine Sea	1	15.9	1	35	0.2× / 5
Other · Philippine Sea	1	14.1	0	—	new / 0
Spills · Gulf of Alaska	1	14	0	—	1.3× / 0.8
Spills · Laccadive Sea	1	14	0	—	new / 0
Spills · North Pacific Ocean	1	14	1	41	0.7× / 1.4
Ordnance · North Pacific Ocean	1	12.8	0	—	1.0× / 1
Surveys · Philippine Sea	1	11.5	0	—	0.6× / 1.8
Spills · Chukchi Sea	1	9	1	9	new / 0
Other · South Pacific Ocean	1	8.7	1	8	1.0× / 1
Cable ops · Mediterranean Sea - Western Basin	1	8.5	0	—	5.0× / 0.2
Cable ops · English Channel	1	7.7	0	—	5.0× / 0.2
Surveys · Bay of Biscay	1	7.3	1	7	5.0× / 0.2
Spills · Bering Sea	1	7	1	7	2.5× / 0.4
Missiles · Arctic Ocean	1	6.1	0	—	1.7× / 0.6
Incidents · Mozambique Channel	1	5.6	0	—	1.0× / 1
Cable ops · Eastern China Sea	1	5.5	1	5	new / 0
Surveys · Japan Sea	1	5.2	0	—	new / 0
Missiles · Kara Sea	1	4.8	0	—	new / 0
Other · Japan Sea	1	4.5	1	4	new / 0
Surveys · Caribbean Sea	1	4.4	0	—	1.7× / 0.6
Other · Gulf of Suez	1	4	0	—	new / 0
Exercises · Tasman Sea	1	4	0	—	new / 0
Other · Bering Sea	1	3.1	0	—	5.0× / 0.2
Quakes · Aegean Sea	1	3	0	—	5.0× / 0.2
Icebergs · Barentsz Sea	1	3	0	—	0.8× / 1.2
Derelicts · Bay of Bengal	1	3	0	—	1.7× / 0.6
Derelicts · Beaufort Sea	1	3	0	—	new / 0
Quakes · Bismarck Sea	1	3	0	—	2.5× / 0.4
Quakes · Gulf of Aden	1	3	0	—	new / 0
Containers · Mozambique Channel	1	3	0	—	new / 0
Quakes · North Atlantic Ocean	1	3	0	—	1.0× / 1
Quakes · Philippine Sea	1	3	0	—	0.6× / 1.6
Quakes · South Atlantic Ocean	1	3	0	—	0.6× / 1.6
Containers · South Pacific Ocean	1	3	0	—	new / 0
Exercises · Norwegian Sea	1	2.6	1	31	1.0× / 1
Missiles · Baffin Bay	1	2.1	1	2	new / 0
Nav aids · Bering Sea	1	2	0	—	5.0× / 0.2
Nav aids · Bristol Channel	1	1.9	0	—	5.0× / 0.2
Exercises · Coral Sea	1	1.9	1	1	0.8× / 1.2
Derelicts · Laccadive Sea	1	1.5	0	—	0.6× / 1.6
Exercises · Mediterranean Sea - Western Basin	1	1.3	0	—	0.7× / 1.4
Missiles · Mediterranean Sea - Eastern Basin	1	0.6	1	0	new / 0
Incidents · Andaman or Burma Sea	1	0.5	1	0	new / 0
Missiles · Japan Sea	1	0.2	0	—	0.7× / 1.4
Other · Indian Ocean	1	0	0	—	0.8× / 1.2
Nav aids · Caribbean Sea	0	307.1	9	261	0.0× / 2.2
Wrecks · South China Sealong running	0	270	9	864	0.0× / 1.4
Wrecks · Persian Gulflong running	0	240	8	562	0.0× / 0.4
Exercises · Aegean Sea	0	193.5	6	169	0.0× / 5.6
Nav aids · Gulf of Mexico	0	180	6	207	0.0× / 3.6
Surveys · Barentsz Sea	0	135	4	166	0.0× / 0.8
Exercises · Ionian Sea	0	90	3	169	— / 0
Other · Persian Gulf	0	90	3	359	0.0× / 0.2
Wrecks · South Atlantic Ocean	0	90	3	163	0.0× / 1
Nav aids · Andaman or Burma Sea	0	60	2	177	0.0× / 1
Surveys · Arctic Ocean	0	60	2	254	— / 0
Wrecks · Inner Seas off the West Coast of Scotland	0	60	2	264	— / 0
Nav aids · Mozambique Channel	0	60	2	259	— / 0
Ordnance · North Sealong running	0	60	2	625	0.0× / 5.8
Volcanic · Philippine Sea	0	60	2	194	— / 0
Restricted · South Atlantic Oceanlong running	0	60	2	545	0.0× / 0.4
Nav aids · Tasman Sea	0	60	2	124	0.0× / 0.8
Other · Gulf of Mexico	0	54.6	1	170	0.0× / 0.6
Cable ops · Aegean Sea	0	30	1	198	0.0× / 1
Missiles · Aegean Sea	0	30	1	169	0.0× / 1
Other · Arafura Sea	0	30	1	84	— / 0
Cable ops · Black Sea	0	30	1	155	0.0× / 0.2
Nav aids · Black Sea	0	30	1	76	0.0× / 0.2
Volcanic · Caribbean Sea	0	30	1	79	0.0× / 0.2
Wrecks · Caribbean Sea	0	30	1	99	0.0× / 0.2
Other · Coral Sea	0	30	1	99	0.0× / 0.8
Nav aids · Gulf of California	0	30	1	134	0.0× / 0.2
Nav aids · Gulf of Thailandlong running	0	30	1	622	— / 0
Wrecks · Japan Sea	0	30	1	160	— / 0
Other · Mediterranean Sea - Eastern Basin	0	30	1	279	0.0× / 0.6
Other · Mozambique Channel	0	30	1	72	— / 0
Volcanic · Mozambique Channellong running	0	30	1	636	— / 0
Cable ops · Persian Gulf	0	30	1	220	0.0× / 1
Nav aids · Persian Gulflong running	0	30	1	441	0.0× / 0.2
Mines · Persian Gulf	0	30	1	178	— / 0
Restricted · Persian Gulflong running	0	30	1	805	0.0× / 0.6
Wrecks · Red Sealong running	0	30	1	564	0.0× / 0.2
Exercises · South China Sea	0	30	1	97	0.0× / 3.6
Structures · South China Sealong running	0	30	1	583	— / 0
Surveys · South China Sealong running	0	30	1	657	0.0× / 2
Incidents · Caribbean Sea	0	28	0	—	0.0× / 4.4
Surveys · Bering Sea	0	24.6	0	—	0.0× / 0.2
Surveys · Arabian Sea	0	22	0	—	0.0× / 0.8
Cable ops · Caribbean Sea	0	20	0	—	0.0× / 0.6
Surveys · Tyrrhenian Sea	0	19.7	0	—	— / 0
Cable ops · Norwegian Sea	0	18.8	0	—	0.0× / 0.8

Cite: seahazards.com Sea Ledger, 2021-06, 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.