Sea Ledger, April 2013

2013-04-01 to 2013-04-30 · archive

issued: 493
warning-days in force: 7,464
in force at month end: 258
sea × type cells: 206

baseline: same month, previous 5 years (2012-04, 2011-04, 2010-04, 2009-04, 2008-04)

By type

type	issued	warning-days	in force at end
Incidents	120	625.2	22
Cable ops	72	1,104.4	39
Exercises	70	747.8	22
Nav aids	44	1,884.3	64
Derelicts	36	134.1	4
Quakes	34	102	2
Icebergs	33	45.6	3
Missiles	28	215.2	8
Other	16	319.9	13
Surveys	16	1,110.8	38
Piracy	8	47.4	6
Debris	6	18	0
Spills	4	87	2
Wrecks	4	671.6	22
Restricted	1	192.4	7
Ordnance	1	38.5	2
War risk	0	60	2
Structures	0	30	1
Volcanic	0	30	1

By sea and type · 200 cells, most issued first

cell	issued	warning-days	at end	longest d	vs 5 y
Cable ops · South Atlantic Ocean	35	272.7	10	36	1.4× / 24.6
Icebergs · Labrador Seasurge	26	27.3	2	27	7.7× / 3.4
Incidents · Indian Oceansurge	25	18.9	2	67	9.6× / 2.6
Incidents · North Pacific Ocean	21	72.6	2	40	1.5× / 14.4
Incidents · North Atlantic Oceansurge	16	147.6	5	37	2.2× / 7.2
Derelicts · Indian Oceansurge	15	50.1	1	32	7.5× / 2
Nav aids · South Atlantic Oceansurgelong running	11	417.7	16	1,714	2.4× / 4.6
Nav aids · North Sea	11	316.8	11	298	1.4× / 7.6
Exercises · Mediterranean Sea - Eastern Basinsurge	11	38.7	1	35	4.2× / 2.6
Missiles · North Pacific Ocean	10	74	3	60	1.5× / 6.8
Incidents · South China Sea	9	27	1	29	1.3× / 7
Quakes · North Pacific Ocean	9	25.5	1	29	0.9× / 9.6
Incidents · South Atlantic Ocean	8	58.3	3	21	1.5× / 5.2
Incidents · Mediterranean Sea - Eastern Basinsurge	8	51.1	2	34	10× / 0.8
Surveys · South Atlantic Oceansurge	7	220.5	8	120	2.7× / 2.6
Cable ops · North Atlantic Ocean	6	122.7	5	178	1.6× / 3.8
Exercises · Bay of Bengal	6	91.4	2	34	1.1× / 5.4
Exercises · Arabian Sea	6	63.2	1	34	1.2× / 5
Exercises · Philippine Seasurge	6	46	3	19	2.0× / 3
Exercises · South Atlantic Ocean	6	30.1	3	18	0.7× / 8.2
Quakes · South Pacific Ocean	6	18	0	—	0.6× / 9.4
Exercises · Yellow Sea	5	45.7	1	34	1.0× / 5.2
Incidents · Mozambique Channelsurge	5	31.6	3	22	5.0× / 1
Incidents · South Pacific Ocean	5	15.3	0	—	0.8× / 6
Icebergs · South Atlantic Oceansurge	5	11.7	1	29	3.1× / 1.6
Nav aids · North Atlantic Ocean	4	254.5	8	213	1.1× / 3.6
Cable ops · Arabian Sea	4	97.1	3	127	1.7× / 2.4
Nav aids · Irish Sea and St. George's Channelsurge	4	60.9	2	41	2.0× / 2
Exercises · North Pacific Ocean	4	38.1	1	36	0.3× / 13.6
Cable ops · Black Seanew	4	35.4	2	47	new / 0
Cable ops · Mediterranean Sea - Eastern Basinsurge	4	27.6	2	70	3.3× / 1.2
Exercises · Black Seasurge	4	25.9	0	—	2.5× / 1.6
Piracy · Gulf of Guineanew	4	23.5	3	30	new / 0
Derelicts · Southern Oceannew	4	6.7	0	—	new / 0
Derelicts · North Pacific Ocean	4	4.8	1	28	1.1× / 3.8
Incidents · Philippine Sea	4	1.9	0	—	1.1× / 3.6
Cable ops · North Seasurge	3	95	4	93	2.1× / 1.4
Incidents · Caribbean Seasurge	3	69.1	1	52	2.1× / 1.4
Nav aids · Inner Seas off the West Coast of Scotland	3	40.4	2	60	0.8× / 3.8
Missiles · South Atlantic Oceansurge	3	28.2	0	—	2.5× / 1.2
Missiles · Barentsz Seasurge	3	21.3	1	34	3.0× / 1
Exercises · Baltic Sea	3	19	0	—	1.5× / 2
Other · Caribbean Seasurge	3	16.8	1	15	15× / 0.2
Piracy · South China Sea	3	14.4	3	6	1.1× / 2.6
Missiles · North Atlantic Oceansurge	3	10.2	2	18	2.1× / 1.4
Missiles · South Pacific Ocean	3	10.2	1	14	1.9× / 1.6
Quakes · Philippine Sea	3	10.1	0	—	1.5× / 2
Exercises · Coral Seasurge	3	9.2	1	7	15× / 0.2
Debris · North Atlantic Oceansurge	3	9	0	—	5.0× / 0.6
Quakes · Solomon Seasurge	3	9	0	—	2.1× / 1.4
Incidents · Arabian Seasurge	3	7.4	1	29	2.1× / 1.4
Cable ops · Norwegian Sea	2	99.3	4	32	3.3× / 0.6
Other · North Sea	2	90.6	4	230	1.4× / 1.4
Cable ops · Bay of Bengal	2	87.5	3	181	0.6× / 3.2
Nav aids · English Channellong running	2	73.9	2	390	0.7× / 2.8
Exercises · South China Sea	2	68.6	1	34	1.0× / 2
Surveys · Gulf of Mexico	2	67.2	1	52	5.0× / 0.4
Exercises · Laccadive Sea	2	57.3	2	61	0.7× / 3
Cable ops · Tasman Sea	2	46.6	0	—	2.5× / 0.8
Incidents · Tyrrhenian Sealong running	2	40	2	471	2.5× / 0.8
Exercises · North Atlantic Ocean	2	35.1	3	34	0.3× / 6.2
Spills · Gulf of Mexico	2	28	0	—	0.5× / 4.2
Cable ops · Gulf of Mexico	2	27.4	1	27	0.9× / 2.2
Exercises · Andaman or Burma Sea	2	17.2	0	—	1.7× / 1.2
Other · Mediterranean Sea - Eastern Basin	2	15.3	0	—	2.0× / 1
Surveys · Bay of Bengal	2	14.8	2	7	10× / 0.2
Nav aids · Bay of Bengal	2	14.6	1	13	3.3× / 0.6
Other · South China Sea	2	13.6	1	13	3.3× / 0.6
Missiles · Norwegian Sea	2	12.1	0	—	10× / 0.2
Surveys · South Pacific Ocean	2	11.1	2	10	10× / 0.2
Cable ops · Ceram Sea	2	11	1	11	10× / 0.2
Cable ops · Celtic Sea	2	9.4	0	—	1.7× / 1.2
Quakes · Bismarck Sea	2	6	0	—	3.3× / 0.6
Debris · Indian Ocean	2	6	0	—	5.0× / 0.4
Quakes · Indian Ocean	2	6	0	—	0.3× / 6.6
Quakes · Japan Sea	2	6	0	—	5.0× / 0.4
Derelicts · Japan Seanew	2	3.9	0	—	new / 0
Other · Indian Ocean	2	2.2	0	—	5.0× / 0.4
Incidents · Coral Sea	2	0.3	0	—	0.8× / 2.4
Incidents · Davis Strait	2	0.1	0	—	5.0× / 0.4
Wrecks · South Atlantic Oceanlong running	1	151.2	5	1,084	new / 0
Exercises · Aegean Sea	1	91.7	2	118	new / 0
Nav aids · Arabian Sealong running	1	91	3	690	1.7× / 0.6
Wrecks · Arabian Sea	1	72.5	3	127	1.3× / 0.8
Surveys · Andaman or Burma Sea	1	57.5	2	119	5.0× / 0.2
Wrecks · English Channel	1	52.8	2	58	new / 0
Cable ops · South China Sea	1	50.5	2	90	0.6× / 1.6
Surveys · Mediterranean Sea - Eastern Basin	1	49.4	1	151	0.7× / 1.4
Cable ops · Persian Gulf	1	40.4	1	97	0.7× / 1.4
Exercises · Ionian Sea	1	35.7	1	118	new / 0
Other · North Atlantic Ocean	1	33.4	2	253	2.5× / 0.4
Other · South Atlantic Ocean	1	33	1	75	new / 0
Derelicts · South Pacific Ocean	1	33	1	307	0.7× / 1.4
Wrecks · Indian Ocean	1	31.6	1	132	new / 0
Nav aids · Celtic Sea	1	30.2	1	187	0.6× / 1.8
Nav aids · Bass Strait	1	29.7	1	29	new / 0
Incidents · Laccadive Sea	1	26.2	0	—	2.5× / 0.4
Spills · North Pacific Ocean	1	23	0	—	0.6× / 1.8
Other · Timor Sea	1	13.7	1	13	new / 0
Incidents · Gulf of Mexico	1	13.4	0	—	1.7× / 0.6
Exercises · Indian Ocean	1	12.6	0	—	0.8× / 1.2
Restricted · Mediterranean Sea - Western Basin	1	12.4	1	12	new / 0
Derelicts · Arabian Sea	1	11.8	1	31	5.0× / 0.2
Cable ops · Philippine Sea	1	11.7	0	—	1.7× / 0.6
Missiles · Arabian Sea	1	8	0	—	1.7× / 0.6
Missiles · Japan Sea	1	8	0	—	1.0× / 1
Missiles · Laccadive Sea	1	7.9	0	—	2.5× / 0.4
Exercises · South Pacific Ocean	1	7.3	0	—	0.4× / 2.6
Exercises · Japan Sea	1	6.9	0	—	0.2× / 5.6
Nav aids · Coral Sea	1	6.4	0	—	0.4× / 2.4
Spills · Caribbean Sea	1	6	1	6	new / 0
Missiles · Southern Ocean	1	5.3	0	—	new / 0
Ordnance · Inner Seas off the West Coast of Scotland	1	4.5	1	4	5.0× / 0.2
Surveys · Black Sea	1	4.4	0	—	1.7× / 0.6
Nav aids · Laccadive Sea	1	4.4	1	4	new / 0
Piracy · Indian Ocean	1	4.1	0	—	0.2× / 5.4
Icebergs · Indian Ocean	1	3.6	0	—	new / 0
Exercises · Adriatic Sea	1	3.3	0	—	5.0× / 0.2
Other · South Pacific Ocean	1	3.3	0	—	1.3× / 0.8
Exercises · Red Sea	1	3.1	0	—	5.0× / 0.2
Quakes · Banda Sea	1	3	0	—	0.4× / 2.4
Derelicts · Bay of Biscay	1	3	0	—	new / 0
Quakes · Bering Sea	1	3	0	—	1.3× / 0.8
Derelicts · Caribbean Sea	1	3	0	—	5.0× / 0.2
Quakes · Eastern China Sea	1	3	0	—	5.0× / 0.2
Debris · English Channel	1	3	0	—	new / 0
Other · English Channel	1	3	0	—	1.7× / 0.6
Derelicts · North Atlantic Ocean	1	3	0	—	0.3× / 3.4
Quakes · Persian Gulf	1	3	0	—	new / 0
Quakes · Seto Naikai or Inland Sea	1	3	0	—	new / 0
Derelicts · South Atlantic Ocean	1	3	0	—	2.5× / 0.4
Quakes · South Atlantic Ocean	1	3	0	—	0.4× / 2.8
Derelicts · South China Sea	1	3	0	—	0.8× / 1.2
Icebergs · South Pacific Ocean	1	3	0	—	1.0× / 1
Derelicts · Tasman Sea	1	3	0	—	1.7× / 0.6
Derelicts · Timor Sea	1	3	0	—	2.5× / 0.4
Cable ops · Indian Ocean	1	2.3	0	—	1.7× / 0.6
Derelicts · Mozambique Channel	1	2	0	—	new / 0
Exercises · Bering Sea	1	1.7	0	—	1.0× / 1
Incidents · Timor Sea	1	1.4	0	—	5.0× / 0.2
Incidents · English Channel	1	1.1	0	—	new / 0
Incidents · Labrador Sea	1	1.1	0	—	new / 0
Derelicts · Bismarck Sea	1	0.8	0	—	new / 0
Quakes · North Atlantic Ocean	1	0.7	1	0	5.0× / 0.2
Incidents · Tasman Sea	1	0.3	0	—	1.0× / 1
Incidents · Bay of Biscay	1	0.1	0	—	1.0× / 1
Nav aids · Great Australian Bight	1	0.1	0	—	1.0× / 1
Nav aids · Gulf of Alaska	1	0	0	—	0.4× / 2.6
Surveys · Arctic Oceanlong running	0	240	8	918	0.0× / 0.2
Surveys · Beaufort Sealong running	0	180	6	993	— / 0
Nav aids · Gulf of Mexicolong running	0	90	3	539	0.0× / 2.8
Nav aids · Sea of Okhotsklong running	0	90	3	497	— / 0
Wrecks · Persian Gulf	0	63.5	2	238	— / 0
Surveys · Arabian Sea	0	60	2	117	0.0× / 0.8
Restricted · Black Sea	0	60	2	257	0.0× / 0.2
Nav aids · Kara Sealong running	0	60	2	601	— / 0
War risk · Mediterranean Sea - Eastern Basinlong running	0	60	2	706	— / 0
Other · North Pacific Oceanlong running	0	60	2	379	0.0× / 1.2
Restricted · North Sealong running	0	60	2	617	0.0× / 0.2
Nav aids · South China Sealong running	0	60	2	624	0.0× / 0.2
Surveys · The Northwestern Passages	0	60	2	267	— / 0
Wrecks · The Northwestern Passageslong running	0	60	2	968	— / 0
Nav aids · North Pacific Oceanlong running	0	56.5	1	716	0.0× / 3.4
Nav aids · Mediterranean Sea - Western Basin	0	52.7	1	57	0.0× / 0.8
Nav aids · Andaman or Burma Sea	0	33.6	1	89	0.0× / 0.2
Missiles · Aegean Sea	0	30	1	118	— / 0
Wrecks · Andaman or Burma Sea	0	30	1	98	— / 0
Wrecks · Baltic Sea	0	30	1	102	— / 0
Surveys · Bering Sea	0	30	1	274	— / 0
Nav aids · Caribbean Sea	0	30	1	158	— / 0
Surveys · Chukchi Sea	0	30	1	148	— / 0
Wrecks · Coral Sea	0	30	1	36	— / 0
Nav aids · Eastern China Sealong running	0	30	1	441	— / 0
Nav aids · Indian Ocean	0	30	1	87	0.0× / 0.4
Surveys · Indian Ocean	0	30	1	60	0.0× / 1.4
Wrecks · Irish Sea and St. George's Channel	0	30	1	313	— / 0
Other · Mediterranean Sea - Western Basin	0	30	1	74	— / 0
Cable ops · Mozambique Channel	0	30	1	71	0.0× / 0.8
Restricted · North Atlantic Ocean	0	30	1	123	0.0× / 0.2
Wrecks · North Atlantic Oceanlong running	0	30	1	570	— / 0
Surveys · North Pacific Ocean	0	30	1	270	0.0× / 0.2
Ordnance · North Sealong running	0	30	1	524	0.0× / 0.6
Structures · North Sealong running	0	30	1	624	0.0× / 0.4
Wrecks · North Sea	0	30	1	50	0.0× / 0.2
Volcanic · Philippine Sealong running	0	30	1	366	0.0× / 0.2
Restricted · Sea of Okhotsklong running	0	30	1	565	— / 0
Spills · South Atlantic Oceanlong running	0	30	1	536	— / 0
Wrecks · Yellow Sealong running	0	30	1	498	— / 0
Incidents · Bay of Bengal	0	28	0	—	0.0× / 1.2
Wrecks · Mediterranean Sea - Eastern Basin	0	26.5	0	—	0.0× / 0.4
Cable ops · Mediterranean Sea - Western Basin	0	22.7	0	—	0.0× / 0.8
Surveys · Mozambique Channel	0	18.5	0	—	0.0× / 1.4
Cable ops · Andaman or Burma Sea	0	14	0	—	0.0× / 0.4
Incidents · Ionian Sea	0	12.4	0	—	— / 0
Piracy · Arabian Sea	0	5.4	0	—	0.0× / 5.6
Nav aids · Southern Ocean	0	5.4	0	—	— / 0
Surveys · Sulu Sea	0	5.4	0	—	— / 0
Other · Andaman or Burma Sea	0	5	0	—	— / 0
Ordnance · Mediterranean Sea - Western Basin	0	4	0	—	— / 0
Nav aids · Persian Gulf	0	3.5	0	—	0.0× / 0.2

Cite: seahazards.com Sea Ledger, 2013-04, 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.