Sea Ledger, December 2017

2017-12-01 to 2017-12-31 · archive

issued: 746
warning-days in force: 14,105
in force at month end: 422
sea × type cells: 250

baseline: same month, previous 5 years (2016-12, 2015-12, 2014-12, 2013-12, 2012-12)

By type

type	issued	warning-days	in force at end
Incidents	229	2,095.8	55
Exercises	118	988	26
Icebergs	83	88.6	4
Nav aids	79	4,221	130
Surveys	54	2,284.9	73
Derelicts	46	207.5	7
Missiles	31	227.6	4
Quakes	30	127.6	3
Debris	16	31.5	0
Cable ops	15	195.3	6
Other	11	599.8	18
Piracy	10	78.4	0
Spills	9	148	3
Wrecks	7	2,261.1	74
Containers	5	11.1	2
Ordnance	3	142.4	5
Restricted	0	124	4
Volcanic	0	155	5
Structures	0	31	1
Storms	0	83.6	2
Mines	0	2.9	0

By sea and type · 200 cells, most issued first

cell	issued	warning-days	at end	longest d	vs 5 y
Incidents · South China Seasurge	64	481.1	20	132	2.5× / 25.6
Incidents · Mediterranean Sea - Eastern Basinsurge	40	574.1	6	40	2.5× / 16.2
Icebergs · Labrador Sea	31	36.6	2	32	1.3× / 24
Icebergs · South Atlantic Oceansurge	31	31	1	31	2.2× / 14
Incidents · North Atlantic Ocean	24	245.5	7	45	1.4× / 17.8
Icebergs · Southern Oceansurge	21	21	1	31	26× / 0.8
Exercises · Aegean Seasurgelong running	17	260.5	13	367	3.9× / 4.4
Exercises · Bay of Bengal	15	117.8	2	38	1.9× / 7.8
Incidents · South Atlantic Oceansurge	15	73.4	2	47	2.7× / 5.6
Surveys · South Atlantic Oceansurge	14	308.8	7	199	2.8× / 5
Quakes · South Pacific Ocean	14	42.4	1	32	1.8× / 8
Incidents · North Pacific Ocean	13	130.6	4	128	0.5× / 24.6
Incidents · Timor Seasurge	13	24.6	0	—	33× / 0.4
Exercises · South Atlantic Ocean	12	52.5	1	33	1.4× / 8.4
Debris · North Atlantic Oceansurge	12	19.5	0	—	12× / 1
Exercises · South Pacific Oceansurge	11	48.2	0	—	5.5× / 2
Nav aids · North Atlantic Oceanlong running	10	531.7	16	1,684	1.6× / 6.4
Exercises · Black Seasurge	10	114.6	1	35	2.6× / 3.8
Missiles · Barentsz Seasurge	10	63.2	0	—	2.6× / 3.8
Exercises · North Pacific Ocean	9	90.1	2	38	0.6× / 14.4
Exercises · North Atlantic Ocean	9	85	2	122	1.7× / 5.2
Incidents · South Pacific Ocean	9	41.5	2	43	1.3× / 7
Exercises · Mediterranean Sea - Eastern Basin	8	22.4	0	—	1.3× / 6
Nav aids · South Atlantic Ocean	7	530.7	17	118	1.1× / 6.4
Surveys · Arabian Seasurge	7	144.4	9	55	2.3× / 3
Incidents · Caribbean Sea	7	85.6	2	50	1.1× / 6.6
Derelicts · Indian Oceansurge	7	18.1	1	27	2.5× / 2.8
Nav aids · North Sea	6	228.3	8	179	0.4× / 13.8
Nav aids · Coral Seasurgelong running	6	158.2	7	1,353	2.7× / 2.2
Incidents · Laccadive Seasurge	6	76.6	1	30	5.0× / 1.2
Derelicts · South China Sea	6	59	2	345	1.7× / 3.6
Cable ops · South Atlantic Ocean	6	51.2	1	58	0.2× / 26
Piracy · Gulf of Guineasurge	6	46.2	0	—	10× / 0.6
Derelicts · North Pacific Oceansurge	6	10.7	0	—	3.3× / 1.8
Missiles · Indian Oceansurge	6	10.6	1	29	2.0× / 3
Nav aids · North Pacific Ocean	5	185.9	4	331	1.0× / 4.8
Nav aids · Inner Seas off the West Coast of Scotland	5	129	4	221	1.1× / 4.6
Spills · Gulf of Mexico	5	80	3	43	1.8× / 2.8
Incidents · Gulf of Mexicosurge	5	73.6	3	44	3.6× / 1.4
Exercises · Arabian Sea	5	64	1	34	0.7× / 6.8
Derelicts · South Pacific Oceansurge	5	44	1	31	3.1× / 1.6
Incidents · Philippine Sea	5	33.5	0	—	1.0× / 5.2
Nav aids · Bass Straitsurgelong running	5	32.7	1	974	13× / 0.4
Derelicts · South Atlantic Oceansurge	5	28.9	0	—	2.3× / 2.2
Quakes · North Pacific Ocean	5	15	0	—	0.8× / 6.6
Surveys · Bay of Bengalsurgelong running	4	113.1	3	541	5.0× / 0.8
Surveys · Mediterranean Sea - Eastern Basin	4	85	3	46	1.7× / 2.4
Exercises · Yellow Sea	4	30	0	—	0.4× / 11.2
Exercises · Indian Ocean	4	25.2	0	—	1.7× / 2.4
Incidents · Java Seasurge	4	16.4	0	—	2.9× / 1.4
Derelicts · North Atlantic Ocean	4	12	0	—	1.0× / 4
Surveys · North Seasurge	4	11.4	0	—	6.7× / 0.6
Surveys · Aegean Seasurge	4	9.2	1	9	20× / 0.2
Quakes · Indian Oceansurge	4	9.1	0	—	2.5× / 1.6
Nav aids · English Channelsurge	4	8.9	0	—	2.0× / 2
Exercises · Philippine Seasurge	4	4.2	0	—	2.2× / 1.8
Nav aids · Caribbean Sealong running	3	644.3	19	393	1.4× / 2.2
Nav aids · Gulf of Mexico	3	251.6	6	331	1.1× / 2.6
Nav aids · Indian Oceanlong running	3	93.5	4	903	1.9× / 1.6
Surveys · South China Seasurge	3	84.5	3	138	15× / 0.2
Wrecks · English Channelsurge	3	82.9	3	94	7.5× / 0.4
Surveys · Black Seasurge	3	62.3	2	114	2.1× / 1.4
Surveys · Persian Gulfsurge	3	45.5	3	34	15× / 0.2
Incidents · Gulf of Thailandsurge	3	30.4	2	47	3.0× / 1
Missiles · Southern Oceannew	3	19.4	0	—	new / 0
Missiles · South Pacific Oceansurge	3	14	0	—	2.1× / 1.4
Exercises · Ionian Seasurge	3	11.4	3	4	15× / 0.2
Nav aids · Celtic Sea	3	10.3	2	5	1.4× / 2.2
Derelicts · Laccadive Seasurge	3	8.5	1	19	5.0× / 0.6
Cable ops · North Seasurge	3	5.7	1	30	15× / 0.2
Surveys · North Atlantic Oceanlong running	2	323.9	8	682	1.1× / 1.8
Nav aids · Arabian Sea	2	169.5	6	248	3.3× / 0.6
Ordnance · North Sea	2	62	2	67	10× / 0.2
Wrecks · Laccadive Seanew	2	56	3	205	new / 0
Nav aids · Great Australian Bightlong running	2	33.9	1	760	1.1× / 1.8
Other · Davis Strait	2	31.4	2	15	5.0× / 0.4
Spills · North Atlantic Ocean	2	28	0	—	1.3× / 1.6
Nav aids · Black Sea	2	26.4	1	26	10× / 0.2
Surveys · Gulf of Mexico	2	24	1	53	10× / 0.2
Incidents · Eastern China Sea	2	22	1	46	5.0× / 0.4
Other · North Sea	2	20.9	0	—	0.9× / 2.2
Cable ops · South Pacific Ocean	2	15.2	2	11	5.0× / 0.4
Exercises · Andaman or Burma Sea	2	12.2	0	—	5.0× / 0.4
Nav aids · Mediterranean Sea - Western Basin	2	12.2	1	11	5.0× / 0.4
Nav aids · Labrador Seanew	2	10.3	1	9	new / 0
Cable ops · Sea of Marmaranew	2	9.9	0	—	new / 0
Derelicts · Caribbean Sea	2	6.5	0	—	1.1× / 1.8
Derelicts · Japan Sea	2	6	0	—	10× / 0.2
Derelicts · Mediterranean Sea - Western Basin	2	6	0	—	5.0× / 0.4
Quakes · Molukka Sea	2	6	0	—	2.0× / 1
Incidents · Bismarck Sea	2	5.6	0	—	1.7× / 1.2
Missiles · Philippine Sea	2	4.7	0	—	5.0× / 0.4
Incidents · Malacca Straitnew	2	3.1	1	31	new / 0
Nav aids · Irish Sea and St. George's Channel	2	2.5	0	—	0.8× / 2.6
Other · North Pacific Ocean	2	2.2	0	—	10× / 0.2
Containers · Celtic Seanew	2	2.1	2	2	new / 0
Missiles · North Atlantic Ocean	2	1.6	1	37	0.2× / 8.8
Incidents · Great Australian Bight	2	0.2	0	—	10× / 0.2
Incidents · Coral Sea	2	0.1	0	—	0.4× / 4.8
Nav aids · South Pacific Oceanlong running	1	256.7	7	482	0.7× / 1.4
Wrecks · North Sea	1	155	5	277	1.7× / 0.6
Nav aids · Tasman Sealong running	1	133	4	579	5.0× / 0.2
Other · South China Sealong running	1	72.8	2	1,131	1.0× / 1
Wrecks · Irish Sea and St. George's Channel	1	62	2	356	5.0× / 0.2
Ordnance · Black Sea	1	49.4	2	362	2.5× / 0.4
Surveys · Indian Oceanlong running	1	43.5	2	402	1.0× / 1
Missiles · North Pacific Ocean	1	36.9	1	121	0.2× / 4.8
Exercises · Laccadive Sea	1	36.7	1	34	0.8× / 1.2
Incidents · Indian Ocean	1	35.6	1	178	0.1× / 6.8
Nav aids · Davis Strait	1	34.1	0	—	2.5× / 0.4
Other · North Atlantic Ocean	1	33.8	1	174	0.6× / 1.8
Nav aids · Singapore Straitlong running	1	31.8	2	752	5.0× / 0.2
Nav aids · Arafura Sealong running	1	31.1	1	556	2.5× / 0.4
Spills · North Pacific Ocean	1	26	0	—	0.7× / 1.4
Incidents · Arabian Sea	1	19.5	0	—	0.8× / 1.2
Incidents · Andaman or Burma Sea	1	17.8	0	—	1.0× / 1
Surveys · South Pacific Ocean	1	16.7	1	37	5.0× / 0.2
Incidents · Red Sea	1	16.2	0	—	new / 0
Incidents · Singapore Strait	1	14.1	0	—	2.5× / 0.4
Spills · The Coastal Waters of Southeast Alaska and British Columbia	1	14	0	—	5.0× / 0.2
Surveys · Red Sea	1	12.5	1	12	new / 0
Other · Gulf of Mexico	1	12.3	1	12	0.8× / 1.2
Piracy · South China Sea	1	11.2	0	—	2.5× / 0.4
Incidents · Persian Gulf	1	9.4	0	—	5.0× / 0.2
Nav aids · The Coastal Waters of Southeast Alaska and British Columbia	1	8.7	0	—	0.6× / 1.6
Other · Irish Sea and St. George's Channel	1	8.1	0	—	5.0× / 0.2
Cable ops · Mediterranean Sea - Eastern Basin	1	7.5	1	7	0.8× / 1.2
Piracy · Gulf of Oman	1	7	0	—	1.7× / 0.6
Piracy · Red Sea	1	7	0	—	new / 0
Piracy · Singapore Strait	1	7	0	—	new / 0
Incidents · Mozambique Channel	1	6.6	1	6	0.8× / 1.2
Quakes · South Atlantic Ocean	1	6.4	0	—	0.8× / 1.2
Cable ops · Aegean Sea	1	4.9	0	—	1.7× / 0.6
Missiles · Laccadive Sea	1	4.9	0	—	0.6× / 1.6
Missiles · Aegean Sea	1	4.8	1	4	new / 0
Incidents · Solomon Sea	1	4.8	0	—	2.5× / 0.4
Incidents · Halmahera Sea	1	4.6	1	4	new / 0
Quakes · Bismarck Sea	1	4.2	1	31	1.7× / 0.6
Missiles · Arctic Ocean	1	3.5	0	—	1.7× / 0.6
Containers · Caribbean Sea	1	3	0	—	new / 0
Debris · Coral Sea	1	3	0	—	new / 0
Derelicts · Coral Sea	1	3	0	—	1.0× / 1
Quakes · Coral Sea	1	3	0	—	1.7× / 0.6
Debris · English Channel	1	3	0	—	1.3× / 0.8
Derelicts · Java Sea	1	3	0	—	new / 0
Exercises · Mediterranean Sea - Western Basin	1	3	0	—	2.5× / 0.4
Containers · North Pacific Ocean	1	3	0	—	1.0× / 1
Debris · North Pacific Ocean	1	3	0	—	1.3× / 0.8
Debris · Philippine Sea	1	3	0	—	new / 0
Quakes · Philippine Sea	1	3	0	—	0.8× / 1.2
Quakes · Solomon Sea	1	3	0	—	0.2× / 5.8
Other · Timor Sea	1	3	0	—	5.0× / 0.2
Containers · Yellow Sea	1	3	0	—	new / 0
Missiles · South China Sea	1	2.5	0	—	new / 0
Incidents · Yellow Sea	1	2.4	1	2	new / 0
Exercises · Baltic Sea	1	2	0	—	0.8× / 1.2
Exercises · Caribbean Sea	1	2	0	—	5.0× / 0.2
Surveys · North Pacific Ocean	1	1.8	0	—	5.0× / 0.2
Incidents · Bass Strait	1	1.5	0	—	5.0× / 0.2
Derelicts · Philippine Sea	1	1.4	1	1	0.7× / 1.4
Nav aids · Strait of Gibraltar	1	1.1	0	—	5.0× / 0.2
Exercises · Gulf of Mexico	1	0.9	0	—	0.6× / 1.6
Derelicts · Solomon Sea	1	0.4	1	0	5.0× / 0.2
Wrecks · South China Sealong running	0	558	18	1,329	0.0× / 0.2
Wrecks · Caribbean Sea	0	372	12	349	0.0× / 0.6
Wrecks · Arabian Sealong running	0	193.5	6	437	0.0× / 0.8
Surveys · Arctic Oceanlong running	0	186	6	1,258	— / 0
Surveys · Beaufort Sealong running	0	155	5	1,919	— / 0
Other · Caribbean Sea	0	155	5	345	0.0× / 1
Surveys · The Northwestern Passageslong running	0	155	5	1,973	— / 0
Other · Coral Sealong running	0	124	4	991	0.0× / 0.6
Surveys · Bering Sea	0	93	3	173	— / 0
Wrecks · Gulf of Mexico	0	93	3	290	— / 0
Wrecks · North Atlantic Ocean	0	93	3	335	— / 0
Wrecks · North Pacific Ocean	0	93	3	255	— / 0
Volcanic · Philippine Sealong running	0	93	3	2,072	0.0× / 0.8
Nav aids · South China Sea	0	89.5	2	46	0.0× / 0.2
Nav aids · Bay of Bengal	0	75.5	2	261	0.0× / 0.6
Nav aids · Gulf of California	0	74.8	2	291	— / 0
Wrecks · South Pacific Ocean	0	68.7	2	97	0.0× / 0.2
Storms · Caribbean Sea	0	62	2	110	— / 0
Surveys · Caribbean Sea	0	62	2	353	0.0× / 0.2
Surveys · Gulf of Guinea	0	62	2	88	— / 0
Surveys · Hudson Strait	0	62	2	86	— / 0
Nav aids · Malacca Straitlong running	0	62	2	797	0.0× / 0.2
Nav aids · Mediterranean Sea - Eastern Basinlong running	0	62	2	629	0.0× / 0.2
Wrecks · South Atlantic Ocean	0	62	2	137	0.0× / 0.8
Wrecks · The Northwestern Passages	0	62	2	127	0.0× / 0.2
Missiles · Black Sea	0	61.5	0	—	0.0× / 1
Surveys · Tasman Sea	0	51.6	1	34	0.0× / 0.2
Nav aids · Bristol Channel	0	34.9	1	227	0.0× / 0.2
Other · Hudson Bay	0	34.3	0	—	— / 0
Quakes · Banda Sea	0	33	1	68	0.0× / 1.8
Wrecks · Andaman or Burma Sea	0	31	1	359	— / 0
Cable ops · Black Sea	0	31	1	73	0.0× / 1
Other · Black Sea	0	31	1	128	0.0× / 0.4
Restricted · Black Sealong running	0	31	1	1,670	0.0× / 0.2
Wrecks · Bristol Channel	0	31	1	114	— / 0
Restricted · Caribbean Sea	0	31	1	208	— / 0
Volcanic · Caribbean Sea	0	31	1	245	— / 0

Cite: seahazards.com Sea Ledger, 2017-12, 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.