Sea Ledger, June 2023

2023-06-01 to 2023-06-30 · archive

issued: 729
warning-days in force: 13,971
in force at month end: 454
sea × type cells: 245

baseline: same month, previous 5 years (2022-06, 2021-06, 2020-06, 2019-06, 2018-06)

By type

type	issued	warning-days	in force at end
Exercises	176	1,295	51
Incidents	120	1,118.1	36
Icebergs	94	105.1	5
Nav aids	62	4,593.9	153
Missiles	57	571.1	9
Surveys	53	2,603.5	83
Quakes	40	125.6	2
Towing	24	23.3	1
Cable ops	22	466.9	14
Other	16	614.7	19
Derelicts	16	212.6	6
Debris	16	125.4	4
Spills	12	175	4
Wrecks	5	1,317.6	44
Containers	5	44.6	2
Piracy	3	9	0
Volcanic	3	243	9
Structures	2	119.6	4
Ordnance	2	45.7	3
Mines	1	71	2
Restricted	0	60	2
War risk	0	30	1

By sea and type · 200 cells, most issued first

cell	issued	warning-days	at end	longest d	vs 5 y
Icebergs · Southern Ocean	33	37.9	2	31	1.1× / 30
Missiles · North Atlantic Oceansurge	30	118	4	31	3.1× / 9.6
Icebergs · Labrador Sea	30	35.4	2	31	1.2× / 25.8
Icebergs · South Atlantic Ocean	30	28.8	1	30	1.0× / 30.4
Exercises · North Pacific Ocean	27	257.9	14	65	1.3× / 21.6
Incidents · South China Sea	24	176.7	5	46	1.2× / 20
Towing · North Pacific Oceansurge	24	23.3	1	23	6.3× / 3.8
Incidents · North Atlantic Ocean	22	273.9	7	46	1.8× / 12
Exercises · South Atlantic Oceansurge	19	105.1	2	34	3.4× / 5.6
Quakes · South Pacific Ocean	17	52.5	1	31	1.6× / 11
Exercises · Bay of Bengal	16	66.3	3	32	1.9× / 8.4
Exercises · South Pacific Ocean	15	52.5	0	—	1.6× / 9.2
Incidents · North Pacific Ocean	13	140.7	6	45	0.9× / 14.2
Surveys · South Pacific Oceansurge	11	85.1	3	101	14× / 0.8
Exercises · Bay of Biscaynew	11	13.9	0	—	new / 0
Incidents · Mediterranean Sea - Eastern Basin	10	51.3	4	42	0.9× / 11
Exercises · Celtic Seanew	10	14	0	—	new / 0
Nav aids · South Atlantic Ocean	9	1,339.8	43	322	1.2× / 7.4
Surveys · North Atlantic Ocean	9	828.3	29	180	0.9× / 9.8
Nav aids · North Atlantic Oceanlong running	9	337.8	12	806	1.3× / 6.8
Exercises · Gulf of Mexicosurge	9	90.1	9	32	5.0× / 1.8
Incidents · Indian Ocean	9	49.5	2	38	1.6× / 5.8
Exercises · Andaman or Burma Seasurge	9	30.6	0	—	4.5× / 2
Surveys · South Atlantic Ocean	8	98.6	2	36	0.6× / 14
Exercises · North Atlantic Ocean	8	93.2	1	68	0.9× / 8.4
Exercises · Black Sealong running	8	76.2	2	464	0.6× / 13.2
Exercises · Laccadive Seasurge	8	61.8	2	31	4.4× / 1.8
Missiles · Indian Oceansurge	8	49.5	1	24	2.7× / 3
Cable ops · North Pacific Oceansurge	8	43.4	2	43	5.7× / 1.4
Exercises · Barentsz Seasurge	7	49.3	2	37	2.1× / 3.4
Exercises · Arabian Sea	7	48.8	1	32	1.1× / 6.2
Debris · North Pacific Oceansurge	7	13.5	0	—	35× / 0.2
Nav aids · Coral Sea	6	73.4	3	68	1.4× / 4.2
Exercises · Caribbean Seasurge	6	41.8	5	13	4.3× / 1.4
Nav aids · Caribbean Seasurgelong running	5	824.9	27	864	3.6× / 1.4
Nav aids · North Sealong running	5	188.4	7	386	0.7× / 7
Nav aids · North Pacific Oceanlong running	5	143.5	5	450	1.3× / 3.8
Missiles · Japan Seasurge	5	106.1	1	31	3.6× / 1.4
Missiles · North Pacific Ocean	5	85.9	1	122	1.1× / 4.6
Incidents · South Pacific Ocean	5	68.9	0	—	1.0× / 4.8
Incidents · Bay of Bengalsurge	5	38.5	0	—	4.2× / 1.2
Incidents · Coral Sea	5	1.6	0	—	1.1× / 4.4
Surveys · Norwegian Seasurge	4	148.5	4	76	3.3× / 1.2
Cable ops · North Atlantic Ocean	4	76.9	3	60	0.8× / 5.2
Spills · Gulf of Mexico	4	52	1	38	0.4× / 9.2
Incidents · South Atlantic Ocean	4	33.1	4	47	0.5× / 7.4
Cable ops · Malacca Straitnew	4	19.9	2	11	new / 0
Quakes · Indian Oceansurge	4	9.5	1	23	2.9× / 1.4
Nav aids · Inner Seas off the West Coast of Scotlandsurge	4	5.7	1	19	2.0× / 2
Nav aids · South Pacific Oceanlong running	3	496.3	15	463	0.6× / 5
Volcanic · Philippine Seanewlong running	3	213	8	924	new / 0
Other · Caribbean Seasurgelong running	3	99	3	610	15× / 0.2
Surveys · Indian Oceansurge	3	72.1	3	126	2.1× / 1.4
Spills · North Atlantic Ocean	3	69	2	344	1.1× / 2.6
Incidents · Arabian Sea	3	55.2	0	—	0.9× / 3.4
Other · South Pacific Oceansurge	3	37.6	1	61	3.8× / 0.8
Incidents · Laccadive Sea	3	20.2	0	—	1.9× / 1.6
Exercises · Gulf of Californiasurge	3	19	3	6	7.5× / 0.4
Exercises · Philippine Sea	3	14.5	1	15	0.3× / 10.8
Quakes · North Pacific Ocean	3	12.6	0	—	1.0× / 3
Exercises · Indian Ocean	3	11.1	0	—	0.9× / 3.4
Quakes · Gulf of Adensurge	3	9	0	—	15× / 0.2
Derelicts · Caribbean Seasurge	3	5.3	0	—	2.5× / 1.2
Surveys · Persian Gulflong running	2	262.5	7	414	0.4× / 4.6
Nav aids · Gulf of Mexicolong running	2	246.4	8	819	1.4× / 1.4
Surveys · Sea of Okhotsk	2	93.2	4	43	0.4× / 5.4
Incidents · Mozambique Channel	2	76.7	0	—	3.3× / 0.6
Other · North Atlantic Ocean	2	72	2	186	1.4× / 1.4
Surveys · Caribbean Sea	2	59.3	1	243	2.5× / 0.8
Missiles · Sea of Okhotsk	2	57.6	0	—	10× / 0.2
Derelicts · Bay of Bengallong running	2	45.4	3	378	2.5× / 0.8
Surveys · North Sea	2	37.9	1	28	0.4× / 5
Derelicts · South Atlantic Ocean	2	36	1	104	1.1× / 1.8
Incidents · Gulf of Mexico	2	30.8	1	30	1.4× / 1.4
Spills · North Pacific Ocean	2	30	0	—	1.0× / 2
Structures · North Seanew	2	29.6	1	29	new / 0
Incidents · Philippine Sea	2	21.7	2	44	0.6× / 3.2
Derelicts · Arabian Sea	2	17	0	—	0.9× / 2.2
Wrecks · English Channel	2	16	0	—	3.3× / 0.6
Ordnance · Bay of Biscaynew	2	15.7	2	11	new / 0
Missiles · Mediterranean Sea - Western Basinnew	2	14.7	0	—	new / 0
Exercises · Japan Sea	2	14.2	0	—	0.8× / 2.6
Nav aids · Timor Sea	2	13.9	0	—	2.5× / 0.8
Exercises · Tasman Sea	2	9.2	0	—	5.0× / 0.4
Quakes · South Atlantic Ocean	2	6.9	0	—	1.0× / 2
Quakes · Sea of Okhotsknew	2	6	0	—	new / 0
Quakes · Southern Ocean	2	6	0	—	10× / 0.2
Containers · Arabian Seanew	2	5.6	1	14	new / 0
Other · North Pacific Ocean	2	3.5	0	—	0.7× / 2.8
Debris · Barentsz Seanew	2	3	0	—	new / 0
Nav aids · Davis Strait	2	2.5	0	—	1.1× / 1.8
Wrecks · South Atlantic Oceanlong running	1	182.1	6	399	1.0× / 1
Nav aids · Laccadive Sealong running	1	135.6	5	381	2.5× / 0.4
Cable ops · Persian Gulf	1	126.6	4	242	1.0× / 1
Wrecks · Persian Gulflong running	1	111.2	4	499	2.5× / 0.4
Surveys · Bay of Bengal	1	64.5	2	56	1.0× / 1
Surveys · Gulf of Mexico	1	62.4	3	61	0.7× / 1.4
Surveys · Arabian Sea	1	54.2	0	—	0.7× / 1.4
Nav aids · Irish Sea and St. George's Channellong running	1	53.8	1	365	0.6× / 1.6
Surveys · Bay of Biscay	1	53.2	2	36	2.5× / 0.4
Nav aids · Beaufort Sea	1	49.4	2	323	new / 0
Wrecks · South Pacific Ocean	1	47.7	2	88	1.0× / 1
Nav aids · Celtic Sea	1	47.6	2	315	1.3× / 0.8
Cable ops · Bay of Bengal	1	43.3	0	—	new / 0
Nav aids · Bering Sea	1	42.4	2	189	2.5× / 0.4
Surveys · Gulf of Guinea	1	35.3	2	38	5.0× / 0.2
Surveys · Bass Strait	1	33.2	2	85	5.0× / 0.2
Derelicts · South Pacific Ocean	1	33	1	270	0.7× / 1.4
Missiles · South Atlantic Ocean	1	32.8	1	34	2.5× / 0.4
Nav aids · Indian Ocean	1	32.5	2	45	0.5× / 2.2
Derelicts · Laccadive Sealong running	1	32.2	1	373	0.6× / 1.6
Debris · South Pacific Ocean	1	31	2	155	0.8× / 1.2
Surveys · South China Sea	1	26.4	1	26	2.5× / 0.4
Cable ops · South China Sea	1	23.5	1	23	0.8× / 1.2
Spills · Bering Sea	1	22	0	—	1.3× / 0.8
Surveys · North Pacific Ocean	1	20.6	1	38	1.7× / 0.6
Nav aids · The Northwestern Passages	1	18.9	1	18	new / 0
Nav aids · Great Australian Bight	1	17.7	0	—	0.7× / 1.4
Cable ops · North Sea	1	17.4	0	—	0.5× / 2.2
Cable ops · Greenland Sea	1	17.1	0	—	new / 0
Incidents · Mediterranean Sea - Western Basin	1	15.9	0	—	5.0× / 0.2
Missiles · Barentsz Sea	1	15.7	0	—	0.2× / 5
Derelicts · Mediterranean Sea - Western Basin	1	15.5	0	—	2.5× / 0.4
Other · Gulf of Mexico	1	14.4	0	—	2.5× / 0.4
Exercises · Persian Gulf	1	14.3	0	—	1.7× / 0.6
Incidents · North Sea	1	14.2	0	—	5.0× / 0.2
Mines · Persian Gulf	1	11	0	—	new / 0
Other · Mediterranean Sea - Eastern Basin	1	10.3	1	10	2.5× / 0.4
Other · Japan Sea	1	9.9	0	—	5.0× / 0.2
Incidents · Adriatic Sea	1	9.5	1	9	new / 0
Nav aids · Tasman Sea	1	8.8	0	—	1.7× / 0.6
Exercises · Bering Sea	1	8.4	0	—	5.0× / 0.2
Cable ops · South Atlantic Ocean	1	8	1	7	1.7× / 0.6
Missiles · Black Sea	1	7.4	0	—	0.2× / 4.8
Exercises · Red Sea	1	6.8	0	—	1.3× / 0.8
Incidents · Celtic Sea	1	6.6	1	6	1.3× / 0.8
Incidents · Molukka Sea	1	6.3	0	—	new / 0
Missiles · Norwegian Sea	1	6.3	0	—	2.5× / 0.4
Surveys · Philippine Sea	1	6	0	—	2.5× / 0.4
Surveys · Celtic Sea	1	5.4	0	—	1.7× / 0.6
Nav aids · English Channel	1	4.6	0	—	0.6× / 1.8
Missiles · Laccadive Sea	1	3.6	0	—	1.3× / 0.8
Quakes · Andaman or Burma Sea	1	3	0	—	new / 0
Debris · Arabian Sea	1	3	0	—	new / 0
Quakes · Bering Sea	1	3	0	—	1.3× / 0.8
Quakes · Bismarck Sea	1	3	0	—	2.5× / 0.4
Debris · Black Sea	1	3	0	—	new / 0
Incidents · Caribbean Sea	1	3	0	—	0.5× / 2
Containers · Celtic Sea	1	3	0	—	new / 0
Debris · Celtic Sea	1	3	0	—	5.0× / 0.2
Other · Celtic Sea	1	3	0	—	1.7× / 0.6
Containers · English Channel	1	3	0	—	new / 0
Debris · English Channel	1	3	0	—	5.0× / 0.2
Piracy · Gulf of Guinea	1	3	0	—	0.6× / 1.6
Derelicts · Indian Ocean	1	3	0	—	0.5× / 2.2
Other · Indian Ocean	1	3	0	—	2.5× / 0.4
Quakes · Japan Sea	1	3	0	—	5.0× / 0.2
Icebergs · Kara Sea	1	3	0	—	0.4× / 2.4
Containers · North Atlantic Ocean	1	3	0	—	5.0× / 0.2
Derelicts · North Atlantic Ocean	1	3	0	—	0.3× / 3.8
Quakes · North Atlantic Ocean	1	3	0	—	1.7× / 0.6
Derelicts · North Pacific Ocean	1	3	0	—	0.6× / 1.8
Debris · North Sea	1	3	0	—	new / 0
Quakes · Philippine Sea	1	3	0	—	0.6× / 1.6
Piracy · Red Sea	1	3	0	—	5.0× / 0.2
Quakes · South China Sea	1	3	0	—	5.0× / 0.2
Piracy · South Pacific Ocean	1	3	0	—	new / 0
Debris · Caribbean Sea	1	2.9	0	—	1.7× / 0.6
Incidents · Ionian Sea	1	2.8	1	2	2.5× / 0.4
Incidents · Tasman Sea	1	2.8	0	—	2.5× / 0.4
Other · Gulf of Alaska	1	2	0	—	new / 0
Derelicts · Coral Sea	1	1.9	0	—	0.7× / 1.4
Incidents · Gulf of Aden	1	1.5	1	1	1.7× / 0.6
Spills · South Atlantic Ocean	1	1	0	—	new / 0
Spills · The Coastal Waters of Southeast Alaska and British Columbia	1	1	1	1	1.0× / 1
Incidents · Arafura Sea	1	0.8	1	0	1.3× / 0.8
Incidents · Solomon Sea	1	0.3	0	—	1.7× / 0.6
Wrecks · Arabian Sealong running	0	180.6	6	395	0.0× / 0.8
Exercises · Aegean Sea	0	150	5	179	0.0× / 3.8
Wrecks · Caribbean Sea	0	150	5	282	— / 0
Surveys · The Northwestern Passages	0	150	5	315	— / 0
Wrecks · The Northwestern Passageslong running	0	150	5	666	— / 0
Surveys · Kara Sea	0	120	4	354	0.0× / 0.4
Nav aids · Bay of Biscay	0	90	3	336	— / 0
Wrecks · Laccadive Sea	0	90	3	133	0.0× / 0.4
Nav aids · Persian Gulflong running	0	90	3	402	0.0× / 0.4
Other · Persian Gulf	0	90	3	134	0.0× / 0.4
Other · South Atlantic Ocean	0	90	3	164	0.0× / 1.2
Wrecks · South China Sealong running	0	90	3	1,576	0.0× / 0.8
Surveys · Barentsz Sea	0	83	2	333	0.0× / 0.8
Surveys · Black Sea	0	61	1	148	0.0× / 1.8
Nav aids · Andaman or Burma Sea	0	60	2	284	0.0× / 1
Nav aids · Arabian Sealong running	0	60	2	611	0.0× / 1.6
Mines · Black Sealong running	0	60	2	491	— / 0
Wrecks · Hudson Bay	0	60	2	245	— / 0
Wrecks · North Sealong running	0	60	2	566	0.0× / 1.4
Structures · South Atlantic Ocean	0	60	2	336	0.0× / 1.2
Cable ops · Arabian Sea	0	44.8	0	—	0.0× / 0.2
Missiles · Aegean Sea	0	30	1	179	0.0× / 0.8
Surveys · Andaman or Burma Sea	0	30	1	60	0.0× / 0.2

Cite: seahazards.com Sea Ledger, 2023-06, 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.