Sea Ledger, July 2023

2023-07-01 to 2023-07-31 · archive

issued: 657
warning-days in force: 13,008
in force at month end: 395
sea × type cells: 232

baseline: same month, previous 5 years (2022-07, 2021-07, 2020-07, 2019-07, 2018-07)

By type

type	issued	warning-days	in force at end
Exercises	134	998.4	29
Incidents	107	939.7	30
Icebergs	104	137.6	4
Surveys	65	2,288.7	64
Missiles	47	341.8	10
Nav aids	46	4,679.1	149
Derelicts	38	245.4	5
Quakes	30	82.8	1
Spills	17	251	10
Towing	17	16.1	1
Cable ops	14	352	11
Other	13	566.2	16
Debris	13	114.1	3
Wrecks	6	1,317.9	42
Piracy	3	9	0
Restricted	1	67.8	2
Containers	1	30.7	0
Ordnance	1	87.4	3
Mines	0	62	2
Structures	0	124	4
War risk	0	31	1
Volcanic	0	265.1	8

By sea and type · 200 cells, most issued first

cell	issued	warning-days	at end	longest d	vs 5 y
Icebergs · Southern Ocean	38	56	1	31	1.2× / 30.6
Icebergs · South Atlantic Ocean	29	26.9	1	31	0.9× / 30.8
Exercises · North Pacific Ocean	27	175.1	10	65	1.0× / 27
Incidents · South China Sea	22	230.9	9	44	0.9× / 24.8
Missiles · Indian Oceansurge	18	107.6	2	31	5.0× / 3.6
Towing · North Pacific Oceansurge	17	16.1	1	31	3.1× / 5.4
Incidents · North Pacific Ocean	16	166.7	5	42	0.9× / 16.8
Icebergs · Labrador Sea	16	20	0	—	0.5× / 29.4
Icebergs · North Atlantic Oceansurge	15	16.7	2	14	75× / 0.2
Exercises · Bay of Bengal	14	74.8	1	41	1.4× / 10.4
Surveys · South Pacific Oceansurge	13	111.3	3	132	16× / 0.8
Missiles · North Atlantic Ocean	13	63.7	2	35	1.2× / 10.6
Incidents · Indian Oceansurge	13	29.9	1	38	2.6× / 5
Surveys · North Atlantic Ocean	12	532.6	13	211	1.2× / 9.8
Spills · Gulf of Mexicosurge	12	146	6	35	2.1× / 5.8
Exercises · South Atlantic Ocean	12	102.3	2	39	1.5× / 8
Exercises · Andaman or Burma Seasurge	12	38.9	2	29	3.5× / 3.4
Exercises · Black Sealong running	11	99.3	4	495	0.6× / 19.4
Incidents · North Atlantic Ocean	10	162.5	6	44	0.9× / 11.4
Incidents · South Pacific Ocean	9	46.8	0	—	1.3× / 6.8
Surveys · South Atlantic Ocean	8	94.3	2	67	0.4× / 18
Nav aids · North Atlantic Oceanlong running	7	350.5	12	837	1.2× / 5.8
Cable ops · North Atlantic Ocean	7	93.7	3	81	0.9× / 7.4
Missiles · South Pacific Ocean	7	35.8	2	17	0.8× / 8.8
Exercises · Bay of Biscaynew	7	16.3	0	—	new / 0
Exercises · Laccadive Seasurge	6	52.5	1	33	3.8× / 1.6
Exercises · Arabian Sea	6	45.3	1	33	1.4× / 4.2
Derelicts · South Pacific Oceansurge	6	36	0	—	3.0× / 2
Exercises · North Atlantic Ocean	6	34.7	0	—	1.6× / 3.8
Exercises · South Pacific Ocean	6	29.7	1	27	0.9× / 6.4
Quakes · South Pacific Ocean	6	18.2	0	—	0.6× / 10.2
Quakes · North Pacific Ocean	6	14	1	17	1.0× / 5.8
Nav aids · South Atlantic Ocean	5	1,313	41	353	0.8× / 6.4
Incidents · Gulf of Mexico	5	59.5	3	31	1.8× / 2.8
Icebergs · Laptev Seasurge	5	15	0	—	2.5× / 2
Debris · North Pacific Oceansurge	5	15	0	—	25× / 0.2
Derelicts · Caribbean Sea	5	14	1	25	1.9× / 2.6
Derelicts · Celtic Seasurge	5	11.5	0	—	6.3× / 0.8
Exercises · Celtic Seasurge	5	10.1	0	—	25× / 0.2
Incidents · Coral Sea	5	4.2	1	21	1.3× / 3.8
Nav aids · Coral Sea	4	112.7	4	99	1.4× / 2.8
Missiles · North Pacific Ocean	4	72.3	1	153	0.9× / 4.6
Surveys · Caribbean Seasurge	4	58.4	1	274	3.3× / 1.2
Other · South Pacific Oceannew	4	40.2	1	92	new / 0
Surveys · North Pacific Oceansurge	4	35.6	1	42	2.9× / 1.4
Derelicts · North Atlantic Ocean	4	24.9	0	—	1.0× / 4
Derelicts · Great Australian Bightsurge	4	8.1	0	—	20× / 0.2
Nav aids · South Pacific Oceanlong running	3	456.5	15	494	0.6× / 4.8
Surveys · Kara Sealong running	3	169.3	5	385	0.7× / 4.2
Nav aids · North Sealong running	3	167.3	4	417	0.5× / 6.6
Surveys · Norwegian Sea	3	137	5	71	0.8× / 3.6
Surveys · Indian Oceansurge	3	78.1	2	157	2.1× / 1.4
Incidents · South Atlantic Ocean	3	66.9	1	44	0.3× / 10
Nav aids · Inner Seas off the West Coast of Scotlandsurge	3	32.2	2	31	3.0× / 1
Exercises · Barentsz Sea	3	27	0	—	1.5× / 2
Exercises · Gulf of Mexico	3	24.9	0	—	1.4× / 2.2
Incidents · Bismarck Sea	3	23.2	1	21	1.4× / 2.2
Exercises · Japan Sea	3	22.7	1	17	1.5× / 2
Derelicts · North Pacific Ocean	3	22.1	0	—	1.5× / 2
Other · North Pacific Ocean	3	19.1	0	—	0.4× / 7.2
Exercises · Caribbean Seasurge	3	17.8	0	—	2.1× / 1.4
Nav aids · Irish Sea and St. George's Channelsurge	3	13.9	0	—	3.0× / 1
Quakes · Indian Ocean	3	11.5	0	—	1.4× / 2.2
Nav aids · Timor Seasurge	3	9.8	1	28	7.5× / 0.4
Debris · Barentsz Seanew	3	9	0	—	new / 0
Quakes · Gulf of Alaska	3	3.1	0	—	1.0× / 3
Incidents · Laccadive Seasurge	3	2.8	0	—	5.0× / 0.6
Nav aids · Caribbean Sealong running	2	879.4	29	895	0.8× / 2.4
Nav aids · North Pacific Oceanlong running	2	169	5	481	0.3× / 6.4
Surveys · Gulf of Mexico	2	79.2	3	92	5.0× / 0.4
Nav aids · Arabian Sealong running	2	66.6	2	642	2.5× / 0.8
Spills · North Atlantic Oceanlong running	2	59	2	375	1.0× / 2
Incidents · Mediterranean Sea - Eastern Basin	2	58.5	1	39	0.6× / 3.6
Surveys · Black Sea	2	55.9	1	179	1.4× / 1.4
Surveys · Bass Strait	2	53.7	1	116	10× / 0.2
Derelicts · Bay of Bengal	2	42.4	0	—	2.5× / 0.8
Derelicts · Laccadive Sealong running	2	38.8	1	404	2.5× / 0.8
Derelicts · South Atlantic Ocean	2	37	1	135	2.0× / 1
Incidents · Philippine Sea	2	33.7	0	—	0.8× / 2.6
Surveys · Mediterranean Sea - Western Basin	2	32.3	2	20	2.5× / 0.8
Cable ops · North Pacific Ocean	2	30.2	2	37	1.0× / 2
Cable ops · Malacca Strait	2	21	1	41	10× / 0.2
Surveys · North Sea	2	19.9	1	59	0.5× / 3.8
Spills · North Pacific Ocean	2	19	2	12	0.6× / 3.6
Exercises · Philippine Sea	2	18.5	0	—	0.4× / 5.6
Incidents · Arafura Sea	2	15.9	0	—	1.3× / 1.6
Wrecks · English Channel	2	8.5	1	8	10× / 0.2
Incidents · Celtic Sea	2	6.8	0	—	2.5× / 0.8
Quakes · Coral Sea	2	6	0	—	0.8× / 2.4
Piracy · North Atlantic Ocean	2	6	0	—	10× / 0.2
Quakes · Philippine Sea	2	6	0	—	1.0× / 2
Quakes · South Atlantic Ocean	2	6	0	—	3.3× / 0.6
Exercises · Bering Sea	2	4.6	0	—	2.5× / 0.8
Other · Indian Ocean	2	3.1	0	—	5.0× / 0.4
Incidents · Bay of Bengal	2	2.6	1	2	1.1× / 1.8
Incidents · Timor Sea	2	0.4	0	—	3.3× / 0.6
Nav aids · Gulf of Mexicolong running	1	249.3	8	850	0.5× / 2.2
Wrecks · Hudson Bay	1	75.1	3	276	new / 0
Ordnance · Bay of Biscay	1	73.8	3	42	new / 0
Nav aids · Celtic Sea	1	62	2	346	0.5× / 2
Surveys · Gulf of Guinea	1	41.7	1	69	5.0× / 0.2
Nav aids · The Northwestern Passages	1	38.9	2	49	0.8× / 1.2
Other · North Atlantic Ocean	1	34.6	1	217	0.8× / 1.2
Surveys · Bay of Bengal	1	31.5	2	61	1.7× / 0.6
Spills · The Coastal Waters of Southeast Alaska and British Columbia	1	27	0	—	0.5× / 2
Nav aids · Indian Ocean	1	26.3	0	—	1.0× / 1
Nav aids · Bass Strait	1	24.9	1	24	new / 0
Nav aids · Hudson Strait	1	17.6	1	17	new / 0
Other · Celtic Sea	1	13.6	1	13	new / 0
Cable ops · South Pacific Ocean	1	13.3	0	—	new / 0
Cable ops · Ligurian Sea	1	13	1	12	new / 0
Other · Mediterranean Sea - Eastern Basin	1	11.3	1	41	5.0× / 0.2
Missiles · Barentsz Sea	1	10.7	1	10	0.3× / 3.2
Exercises · Red Sea	1	8.4	0	—	2.5× / 0.4
Nav aids · Arafura Sea	1	7.8	0	—	1.7× / 0.6
Missiles · Coral Sea	1	7.3	0	—	new / 0
Surveys · Solomon Sea	1	7	0	—	5.0× / 0.2
Incidents · Gulf of Aden	1	6.7	0	—	new / 0
Cable ops · Singapore Strait	1	6.5	0	—	new / 0
Surveys · Mediterranean Sea - Eastern Basin	1	6.3	1	6	0.6× / 1.6
Restricted · Black Sea	1	5.8	0	—	5.0× / 0.2
Wrecks · Bay of Bengal	1	5.6	1	5	1.7× / 0.6
Incidents · Mozambique Channel	1	4.3	1	4	1.7× / 0.6
Derelicts · Arabian Sea	1	3.8	1	3	0.6× / 1.6
Wrecks · Eastern China Sea	1	3.7	1	3	new / 0
Containers · Arabian Sea	1	3.4	0	—	5.0× / 0.2
Quakes · Andaman or Burma Sea	1	3	0	—	2.5× / 0.4
Missiles · Andaman or Burma Sea	1	3	0	—	new / 0
Incidents · Arabian Sea	1	3	0	—	1.3× / 0.8
Debris · Black Sea	1	3	0	—	new / 0
Debris · Eastern China Sea	1	3	0	—	new / 0
Debris · English Channel	1	3	0	—	new / 0
Piracy · Gulf of Guinea	1	3	0	—	0.8× / 1.2
Derelicts · Gulf of Mexico	1	3	0	—	1.0× / 1
Derelicts · Kara Sea	1	3	0	—	new / 0
Icebergs · Kara Sea	1	3	0	—	0.5× / 2
Debris · Laccadive Sea	1	3	0	—	new / 0
Quakes · Molukka Sea	1	3	0	—	0.6× / 1.8
Quakes · North Atlantic Ocean	1	3	0	—	5.0× / 0.2
Quakes · Savu Sea	1	3	0	—	new / 0
Quakes · Solomon Sea	1	3	0	—	0.5× / 2.2
Quakes · Southern Ocean	1	3	0	—	1.7× / 0.6
Missiles · Laccadive Sea	1	2.9	0	—	1.7× / 0.6
Exercises · Bali Sea	1	2.6	0	—	new / 0
Exercises · Indian Ocean	1	2.4	0	—	1.3× / 0.8
Other · Gulf of Alaska	1	1.9	0	—	1.7× / 0.6
Exercises · Mozambique Channel	1	1.9	0	—	new / 0
Exercises · Coral Sea	1	1.7	0	—	0.6× / 1.6
Surveys · Ligurian Sea	1	1.3	0	—	new / 0
Wrecks · Malacca Strait	1	0.9	1	0	new / 0
Exercises · Mediterranean Sea - Eastern Basin	1	0.9	0	—	0.1× / 13.2
Derelicts · Coral Sea	1	0.7	1	0	1.0× / 1
Incidents · Gulf of Thailand	1	0.7	0	—	1.7× / 0.6
Nav aids · Bristol Channel	1	0.6	0	—	new / 0
Nav aids · Gulf of Alaska	1	0.6	0	—	0.7× / 1.4
Missiles · Bay of Bengal	1	0.5	1	0	5.0× / 0.2
Debris · Mediterranean Sea - Western Basin	1	0.5	1	0	new / 0
Incidents · Great Australian Bight	1	0.4	0	—	5.0× / 0.2
Incidents · Celebes Sea	1	0.1	0	—	2.5× / 0.4
Derelicts · Indian Ocean	1	0.1	0	—	0.4× / 2.8
Volcanic · Philippine Sealong running	0	248	8	955	0.0× / 0.8
Surveys · Persian Gulflong running	0	205.3	4	445	0.0× / 4.6
Wrecks · South Atlantic Oceanlong running	0	186	6	430	0.0× / 1.4
Wrecks · Arabian Sealong running	0	175	3	426	0.0× / 1.4
Exercises · Aegean Sea	0	155	5	210	0.0× / 1.8
Wrecks · Caribbean Sea	0	155	5	313	0.0× / 0.8
Nav aids · Laccadive Sealong running	0	155	5	412	0.0× / 0.2
Surveys · The Northwestern Passages	0	155	5	346	— / 0
Wrecks · The Northwestern Passageslong running	0	155	5	697	— / 0
Surveys · Sea of Okhotsk	0	124	4	74	0.0× / 2
Wrecks · Persian Gulflong running	0	120.3	3	530	0.0× / 0.8
Cable ops · Persian Gulf	0	112.3	2	204	0.0× / 0.4
Other · Caribbean Sealong running	0	93	3	641	0.0× / 1
Wrecks · Laccadive Sea	0	93	3	164	— / 0
Other · Persian Gulf	0	93	3	165	0.0× / 0.2
Wrecks · South China Sealong running	0	93	3	1,607	0.0× / 1
Other · South Atlantic Ocean	0	77.8	2	195	0.0× / 1.2
Nav aids · Persian Gulflong running	0	67.7	2	433	0.0× / 0.4
Surveys · Barentsz Sea	0	62	2	364	0.0× / 1.4
Nav aids · Beaufort Sea	0	62	2	354	0.0× / 0.2
Nav aids · Bering Sea	0	62	2	220	— / 0
Mines · Black Sealong running	0	62	2	522	— / 0
Structures · South Atlantic Oceanlong running	0	62	2	367	0.0× / 0.8
Surveys · Bay of Biscay	0	61	1	67	0.0× / 0.2
Nav aids · Andaman or Burma Sea	0	58.3	1	315	0.0× / 0.4
Nav aids · Bay of Biscaylong running	0	58.2	1	367	0.0× / 0.2
Wrecks · South Pacific Ocean	0	33.6	1	119	0.0× / 0.4
Debris · South Pacific Ocean	0	33	1	186	0.0× / 1
Missiles · Aegean Sea	0	31	1	210	— / 0
Wrecks · Arafura Sea	0	31	1	91	— / 0
Nav aids · Arctic Ocean	0	31	1	313	— / 0
Surveys · Arctic Ocean	0	31	1	323	0.0× / 0.4
Nav aids · Barentsz Sea	0	31	1	261	— / 0
Debris · Bay of Biscay	0	31	1	327	— / 0
Other · Bay of Biscay	0	31	1	194	— / 0
Other · Black Sea	0	31	1	134	— / 0
War risk · Black Sealong running	0	31	1	496	— / 0
Wrecks · Coral Sealong running	0	31	1	395	0.0× / 0.6
Other · English Channel	0	31	1	189	0.0× / 0.2
Nav aids · Gulf of Californialong running	0	31	1	472	— / 0

Cite: seahazards.com Sea Ledger, 2023-07, 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.