Sea Ledger, August 2017

2017-08-01 to 2017-08-31 · archive

issued: 649
warning-days in force: 13,140
in force at month end: 446
sea × type cells: 261

baseline: same month, previous 5 years (2016-08, 2015-08, 2014-08, 2013-08, 2012-08)

By type

type	issued	warning-days	in force at end
Incidents	138	1,446.1	52
Exercises	109	1,167.4	33
Nav aids	91	3,347.6	108
Surveys	70	2,774.6	100
Icebergs	54	97.2	2
Missiles	32	243.5	11
Cable ops	29	512.8	18
Derelicts	23	152.1	7
Quakes	23	65.5	2
Other	17	633.2	21
Spills	17	213	6
Wrecks	15	1,895.1	65
Restricted	9	187.3	8
Ordnance	8	147.2	6
Debris	7	19.6	0
Piracy	4	35.4	0
Storms	3	2	1
Mines	0	14.4	0
Volcanic	0	155	5
Structures	0	31	1

By sea and type · 200 cells, most issued first

cell	issued	warning-days	at end	longest d	vs 5 y
Incidents · South China Sea	29	283.9	7	46	1.4× / 21
Incidents · North Pacific Ocean	25	253	8	46	0.9× / 26.4
Icebergs · Labrador Sea	19	23.9	0	—	0.7× / 29.2
Incidents · Mediterranean Sea - Eastern Basin	18	212.1	13	39	1.4× / 12.6
Exercises · Black Sea	18	168.2	4	93	1.9× / 9.6
Exercises · North Pacific Ocean	17	148.5	6	66	1.0× / 16.6
Nav aids · North Sea	15	205.8	6	57	1.4× / 11
Exercises · North Atlantic Oceansurge	14	50.1	1	30	2.9× / 4.8
Incidents · North Atlantic Ocean	13	202.4	4	48	1.0× / 13.2
Surveys · South China Seasurge	11	135.4	4	152	18× / 0.6
Exercises · South Atlantic Ocean	10	40.2	2	28	1.2× / 8.4
Icebergs · Laptev Seasurge	10	32.9	0	—	13× / 0.8
Nav aids · South Atlantic Ocean	9	317	10	127	1.6× / 5.6
Nav aids · South Pacific Oceansurge	9	277.3	8	360	4.5× / 2
Surveys · South Atlantic Oceansurge	9	151.4	5	134	2.1× / 4.2
Icebergs · North Atlantic Oceansurge	9	9.8	2	8	7.5× / 1.2
Surveys · Bay of Bengalsurgelong running	8	140.7	4	419	13× / 0.6
Spills · Gulf of Mexico	8	81	4	29	1.8× / 4.4
Missiles · Black Seasurge	8	80.1	2	31	2.5× / 3.2
Missiles · North Pacific Ocean	7	47.4	2	152	1.3× / 5.6
Incidents · South Pacific Ocean	7	26.9	3	30	0.7× / 9.8
Quakes · South Pacific Ocean	7	21	0	—	0.8× / 8.6
Icebergs · Southern Oceannew	7	9	0	—	new / 0
Nav aids · North Pacific Oceansurge	6	188.8	5	316	2.0× / 3
Cable ops · South Atlantic Ocean	6	60.9	2	62	0.4× / 13.8
Other · North Seasurge	6	56.7	2	102	6.0× / 1
Surveys · North Seasurge	6	51.4	2	65	7.5× / 0.8
Nav aids · Indian Oceanlong running	6	44.8	2	781	1.5× / 4
Incidents · Philippine Seasurge	6	44	0	—	2.3× / 2.6
Incidents · South Atlantic Ocean	6	39.9	4	32	0.8× / 7.4
Incidents · Coral Sea	6	35.7	0	—	1.4× / 4.2
Missiles · North Atlantic Ocean	6	23.1	3	34	1.1× / 5.6
Icebergs · Davis Straitsurge	6	12.6	0	—	5.0× / 1.2
Exercises · Philippine Sea	6	5.1	1	5	1.1× / 5.4
Nav aids · Gulf of Mexicosurge	5	254.3	10	209	2.3× / 2.2
Nav aids · Coral Sealong running	5	131.8	4	1,231	1.4× / 3.6
Cable ops · Caribbean Seasurge	5	68.3	4	258	3.6× / 1.4
Incidents · Indian Ocean	5	54.7	1	56	0.4× / 12.6
Exercises · Yellow Sea	5	22.1	0	—	0.5× / 9.6
Nav aids · Arabian Seasurge	4	176.2	4	126	10× / 0.4
Surveys · Caribbean Seanew	4	96.1	3	231	new / 0
Nav aids · Inner Seas off the West Coast of Scotland	4	86.1	3	99	1.7× / 2.4
Exercises · Bay of Bengal	4	58.9	1	35	0.8× / 4.8
Surveys · Black Seasurge	4	57.9	3	56	6.7× / 0.6
Incidents · Gulf of Mexico	4	57.4	3	40	1.3× / 3
Derelicts · South China Seasurge	4	57	2	223	2.5× / 1.6
Restricted · Black Seasurgelong running	4	51.9	3	1,548	3.3× / 1.2
Missiles · Barentsz Sea	4	26.6	1	18	1.2× / 3.4
Exercises · Mediterranean Sea - Eastern Basin	4	15.4	0	—	0.7× / 5.6
Exercises · South China Sea	4	14.6	0	—	1.2× / 3.4
Exercises · South Pacific Ocean	4	14	0	—	1.3× / 3
Derelicts · Indian Ocean	4	13.6	1	22	0.9× / 4.4
Restricted · South Atlantic Oceansurge	4	8	1	7	20× / 0.2
Exercises · Bering Sea	4	3.4	1	24	1.8× / 2.2
Ordnance · Bristol Channelnew	4	2.6	0	—	new / 0
Nav aids · Caribbean Seasurgelong running	3	540.2	20	434	3.0× / 1
Surveys · North Atlantic Oceanlong running	3	283.7	10	560	0.6× / 5
Wrecks · North Seasurge	3	173.3	6	155	5.0× / 0.6
Surveys · Mediterranean Sea - Eastern Basinsurge	3	124.2	5	119	15× / 0.2
Ordnance · North Seasurge	3	62.1	3	54	3.8× / 0.8
Surveys · Barentsz Seasurge	3	48.7	4	44	3.8× / 0.8
Cable ops · Davis Straitnew	3	47.1	2	22	new / 0
Cable ops · North Sea	3	42	0	—	0.4× / 8
Nav aids · Celtic Seasurge	3	35.6	1	141	2.5× / 1.2
Cable ops · Arabian Seasurge	3	17.5	0	—	5.0× / 0.6
Icebergs · Kara Seasurge	3	9	0	—	15× / 0.2
Nav aids · Irish Sea and St. George's Channel	3	7.9	0	—	1.3× / 2.4
Quakes · Indian Ocean	3	6.3	1	25	1.4× / 2.2
Nav aids · English Channel	3	5.1	0	—	1.3× / 2.4
Nav aids · The Coastal Waters of Southeast Alaska and British Columbiasurge	3	4.8	0	—	2.1× / 1.4
Storms · Gulf of Mexiconew	3	2	1	2	new / 0
Surveys · Norwegian Seanew	2	403	13	139	new / 0
Surveys · Kara Sea	2	185.8	6	66	2.5× / 0.8
Nav aids · North Atlantic Oceanlong running	2	169.3	5	1,562	0.5× / 4.4
Surveys · The Northwestern Passageslong running	2	117	4	1,851	2.0× / 1
Wrecks · South Atlantic Ocean	2	115.3	5	202	2.5× / 0.8
Surveys · Sea of Okhotsk	2	85.2	3	269	5.0× / 0.4
Other · South China Sealong running	2	82	2	1,009	1.4× / 1.4
Other · Hudson Baynew	2	64.1	2	45	new / 0
Exercises · Arabian Sea	2	38	1	36	0.6× / 3.4
Cable ops · South Pacific Oceannew	2	37.8	1	24	new / 0
Incidents · Mediterranean Sea - Western Basin	2	35.6	1	31	1.3× / 1.6
Spills · Gulf of Alaska	2	34	0	—	2.0× / 1
Spills · North Pacific Ocean	2	34	1	32	1.3× / 1.6
Wrecks · English Channel	2	33.9	1	69	2.5× / 0.8
Nav aids · Hudson Straitnew	2	33.7	2	17	new / 0
Exercises · Norwegian Seanew	2	32.1	0	—	new / 0
Exercises · Sea of Okhotsk	2	29.1	1	36	2.5× / 0.8
Spills · The Coastal Waters of Southeast Alaska and British Columbia	2	22	1	23	2.0× / 1
Derelicts · Gulf of Mexico	2	20.6	0	—	2.0× / 1
Incidents · Gulf of Thailand	2	15.3	2	8	10× / 0.2
Exercises · Caribbean Sea	2	13	0	—	1.7× / 1.2
Piracy · Red Seanew	2	10.6	0	—	new / 0
Missiles · Norwegian Sea	2	9.2	0	—	10× / 0.2
Quakes · North Pacific Ocean	2	7.9	0	—	0.3× / 6.8
Missiles · Indian Ocean	2	7.6	0	—	5.0× / 0.4
Quakes · Bismarck Sea	2	6	0	—	2.5× / 0.8
Debris · North Atlantic Ocean	2	6	0	—	2.5× / 0.8
Derelicts · North Atlantic Ocean	2	6	0	—	0.5× / 4.2
Quakes · South Atlantic Ocean	2	6	0	—	0.9× / 2.2
Derelicts · Bay of Bengal	2	5.9	1	23	1.0× / 2
Exercises · Indian Ocean	2	5.5	0	—	2.0× / 1
Other · The Northwestern Passages	2	4.8	0	—	2.0× / 1
Derelicts · Mediterranean Sea - Western Basin	2	4.4	1	24	5.0× / 0.4
Other · North Pacific Ocean	2	3	0	—	3.3× / 0.6
Wrecks · Gulf of Guineanew	2	1.8	1	1	new / 0
Wrecks · South China Sealong running	1	521.3	17	1,207	1.7× / 0.6
Surveys · Arctic Oceanlong running	1	248	8	1,136	1.0× / 1
Nav aids · Tasman Sealong running	1	93.8	3	457	0.6× / 1.6
Wrecks · Arabian Sea	1	92.5	3	315	1.3× / 0.8
Nav aids · Andaman or Burma Sea	1	90	3	178	2.5× / 0.4
Cable ops · Persian Gulf	1	84.2	3	261	2.5× / 0.4
Surveys · Japan Sea	1	80.3	3	92	new / 0
Wrecks · Irish Sea and St. George's Channel	1	62	2	234	5.0× / 0.2
Incidents · Caribbean Sea	1	50	1	40	0.2× / 5.4
Nav aids · Bristol Channel	1	48.7	2	105	5.0× / 0.2
Nav aids · Kara Sea	1	44.1	1	31	5.0× / 0.2
Surveys · Laptev Sea	1	34.7	2	37	new / 0
Nav aids · Bay of Bengal	1	32.1	1	139	1.3× / 0.8
Nav aids · Bass Straitlong running	1	31.7	1	852	1.3× / 0.8
Surveys · Celtic Sea	1	31.7	2	72	2.5× / 0.4
Derelicts · South Pacific Ocean	1	31	1	32	0.3× / 3
Exercises · Laccadive Sea	1	30.7	1	34	0.6× / 1.8
Surveys · Labrador Sea	1	27.3	1	49	2.5× / 0.4
Surveys · North Pacific Ocean	1	24.6	1	50	1.7× / 0.6
Nav aids · Bering Sea	1	23.5	1	23	new / 0
Nav aids · Red Sea	1	22.2	1	22	new / 0
Wrecks · Mozambique Channel	1	21.3	1	21	new / 0
Ordnance · Sea of Azov	1	20.5	1	20	2.5× / 0.4
Cable ops · North Pacific Ocean	1	19.5	1	19	new / 0
Incidents · Adriatic Sea	1	18.8	0	—	0.8× / 1.2
Incidents · Laccadive Sea	1	18.2	0	—	0.7× / 1.4
Incidents · The Northwestern Passages	1	17.9	0	—	0.8× / 1.2
Cable ops · Andaman or Burma Sea	1	17.5	1	17	new / 0
Exercises · Gulf of Mexico	1	15.9	0	—	0.6× / 1.6
Wrecks · Sea of Okhotsk	1	15.6	1	15	new / 0
Cable ops · North Atlantic Ocean	1	15.5	1	15	0.1× / 7.6
Surveys · Malacca Strait	1	14.7	1	14	new / 0
Incidents · Arabian Sea	1	14.6	1	14	1.0× / 1
Incidents · Eastern China Sea	1	14.6	1	14	5.0× / 0.2
Spills · Beaufort Sea	1	14	0	—	new / 0
Spills · Bering Sea	1	14	0	—	5.0× / 0.2
Spills · North Atlantic Ocean	1	14	0	—	0.3× / 3.6
Piracy · Gulf of Guinea	1	12.8	0	—	1.3× / 0.8
Incidents · Bismarck Sea	1	11.9	1	31	5.0× / 0.2
Incidents · Arafura Sea	1	11	0	—	1.7× / 0.6
Other · Mozambique Channel	1	10.7	1	10	5.0× / 0.2
Surveys · Coral Sea	1	9.9	1	9	new / 0
Cable ops · Makassar Strait	1	9	0	—	new / 0
Surveys · Baffin Bay	1	8.5	1	8	new / 0
Incidents · Solomon Sea	1	7.2	0	—	1.3× / 0.8
Piracy · South China Sea	1	7	0	—	1.7× / 0.6
Missiles · Laccadive Sea	1	6.9	0	—	1.3× / 0.8
Exercises · Baltic Sea	1	6.7	0	—	0.5× / 2.2
Other · Black Sea	1	6.5	1	6	new / 0
Exercises · Gulf of Thailand	1	6.4	0	—	new / 0
Wrecks · The Northwestern Passages	1	6	1	5	1.7× / 0.6
Missiles · Bay of Bengal	1	5.8	1	5	0.8× / 1.2
Missiles · South Pacific Ocean	1	5.8	1	5	0.6× / 1.6
Cable ops · Celtic Sea	1	5.6	0	—	1.3× / 0.8
Exercises · Barentsz Sea	1	4.4	0	—	5.0× / 0.2
Incidents · Ceram Sea	1	3.8	1	3	2.5× / 0.4
Exercises · Coral Sea	1	3.5	0	—	0.4× / 2.8
Restricted · Sea of Azov	1	3.4	0	—	2.5× / 0.4
Surveys · East Siberian Sea	1	3.2	1	3	new / 0
Quakes · Banda Sea	1	3	0	—	1.0× / 1
Derelicts · Caribbean Sea	1	3	0	—	0.5× / 2.2
Quakes · Celebes Sea	1	3	0	—	new / 0
Debris · Coral Sea	1	3	0	—	5.0× / 0.2
Quakes · Eastern China Sea	1	3	0	—	5.0× / 0.2
Debris · Indian Ocean	1	3	0	—	1.7× / 0.6
Derelicts · Japan Sea	1	3	0	—	new / 0
Derelicts · Laccadive Sea	1	3	0	—	5.0× / 0.2
Debris · Mediterranean Sea - Western Basin	1	3	0	—	new / 0
Debris · North Pacific Ocean	1	3	0	—	1.3× / 0.8
Quakes · Philippine Sea	1	3	0	—	0.6× / 1.8
Derelicts · Red Sea	1	3	0	—	new / 0
Quakes · Solomon Sea	1	3	0	—	0.8× / 1.2
Quakes · Tasman Sea	1	3	0	—	1.3× / 0.8
Nav aids · Beaufort Sea	1	2.5	0	—	1.7× / 0.6
Exercises · Mediterranean Sea - Western Basin	1	2.2	0	—	5.0× / 0.2
Other · Norwegian Sea	1	2.2	1	2	new / 0
Debris · English Channel	1	1.6	0	—	new / 0
Exercises · Japan Sea	1	1.6	1	1	5.0× / 0.2
Incidents · Mozambique Channel	1	1.6	1	1	0.5× / 2
Exercises · Celebes Sea	1	1.3	0	—	5.0× / 0.2
Derelicts · North Pacific Ocean	1	1	1	0	0.5× / 2.2
Incidents · Savu Sea	1	0.7	0	—	new / 0
Surveys · Andaman or Burma Sea	1	0.6	1	0	5.0× / 0.2
Derelicts · Celtic Sea	1	0.6	0	—	1.0× / 1
Incidents · Baffin Bay	1	0.5	0	—	2.5× / 0.4
Cable ops · Tyrrhenian Sea	1	0.4	1	0	new / 0
Incidents · Celebes Sea	1	0.3	0	—	new / 0
Quakes · Gulf of Alaska	1	0.3	1	0	new / 0
Incidents · Tasman Sea	1	0	0	—	1.0× / 1
Exercises · Aegean Sea	0	340.5	10	245	0.0× / 1
Wrecks · Caribbean Sealong running	0	310	10	411	— / 0
Other · Coral Sealong running	0	139	4	869	0.0× / 0.2
Surveys · Beaufort Sealong running	0	124	4	1,797	0.0× / 0.2
Other · Caribbean Sea	0	124	4	223	0.0× / 0.2

Cite: seahazards.com Sea Ledger, 2017-08, 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.