Towed array / streamer
Equipment towed a long way behind a vessel — sonar, a hydrophone cable, a sampling sled — invisible at the surface.
A towed array can stretch hundreds of metres to several kilometres behind the vessel that tows it, below the surface where other ships cannot see it. Crossing astern of a survey ship or a warship towing sonar risks fouling the cable, which is why warnings give its length and ask ships to pass well clear, and never between the vessel and its tail buoy.
Naval ships, seismic survey vessels and research vessels all tow arrays; the warning usually says which, and how long.
What the archive shows
11,436 messages in this archive use “Towed array / streamer”, the earliest issued 1985-02-25 and the latest 2026-09-15. 9 of them are in force in the latest lists we collected. A hazard reported again and again counts once per message.
The largest yearly count is 2000, with 1,567 messages. Collection is incomplete between 2024-05 and 2026-08-17, so 2024, 2025 and 2026 are not comparable with fully collected years.
Cable ops accounts for 8,962 of 11,436 recorded messages (78%), the largest warning type group in this selection.
Located messages that use it fall in 77 sea areas; the most frequent are South Atlantic Ocean (5,121), North Atlantic Ocean (661) and Arabian Sea (348).
Its use is spread fairly evenly through the year: the busiest month, January, has 1,057 messages and the quietest, November, 861.
By warning series: HYDROLANT 8,138, HYDROPAC 2,414, NAVAREA IV 537 and HYDROARC 315, and 6 more.
Messages using it, by year of issue
By month of issue, all years
Where it appears · 77 sea areas
- South Atlantic Ocean 5,121
- North Atlantic Ocean 661
- Arabian Sea 348
- South China Sea 300
- North Sea 294
- Bay of Bengal 271
- Gulf of Mexico 220
- Norwegian Sea 198
- Mediterranean Sea - Eastern Basin 147
- Barentsz Sea 97
- Black Sea 95
- Sea of Okhotsk 93
In force now · 9
- HYDROARC 191/26 · Surveys · Norwegian Sea2026-08-28 · in force
…SEA. 1. SURVEY OPERATIONS IN PROGRESS UNTIL FURTHER NOTICE BY M/V AMAZON CONQUEROR TOWING 12 10000 METER LONG CABLES IN AREA BOUND BY 65-40.80N 005-19.70E, 65-42.20N 006-52.30E, 64-33.50N 006-04.80E,…
Survey operations in progress until further notice by M/V amazon conqueror towing 12 10000 meter long cables… → - NAVAREA 7 246/26 · Cable ops · South Atlantic Ocean2026-08-24 · in force
…RIVER MOUTH 2. CHART SAN 1 3. M/V RAMFORM VICTORY CONDUCTING SEISMIC SURVEY OPERATIONS TOWING 12 SEISMIC CABLES WITH LENGTH 2.6 NM IN AREAS BOUNDED BY THE FOLLOWING COORDINATES A. 06 - 07.3 S 011 -…
NAVAREA VII 246 of 2026 (24 aug 26) 1. south atlantic ocean - ne sector - offshore orange river mouth 2.… → - NAVAREA I 171/26 · Cable ops · North Sea2026-08-15 · in force
NORTH SEA. FRIGG FIELD. 1. SEISMIC SURVEY IN PROGRESS BY RSV AMAZON CONQUEROR TOWING 8 X 1 MILE LONG CABLES IN AREA BOUND BY 60-00.9N 001-57.8E, 60-01.7N 002-13.3E, 59-48.7N 002-15.8E, 59-47.2N…
Seismic survey in progress by rsv amazon conqueror towing 8 X 1 mile long cables in area bound by 60-00.9N… → - HYDROPAC 2249/26 · Surveys · South China Sea2026-08-06 · in force
…SOUTH CHINA SEA. MALAYSIA. 1. SURVEY OPERATIONS IN PROGRESS UNTIL 31 DEC BY M/V PXGEO 2 TOWING EIGHT FIVE MILE LONG CABLES IN AREA BOUND BY 06-33.00N 103-25.00E, 06-50.00N 102-58.00E, 06-55.00N 103-14.00E,…
Survey operations in progress until 31 dec by M/V pxgeo 2 towing eight five mile long cables in area bound… → - NAVAREA XI 356/26 · Cable ops · South China Sea2026-08-06 · in force
GULF OF THAILAND AND SOUTH CHINA SEA, SOUTHERN PART. SEISMIC SURVEY WORKS BY M/V PXGEO 2 TOWING EIGHT CABLES, EACH 5 MILE LONG. UNTIL 31 DEC 2026. AREA BOUNDED BY 06-33N 103-25E 06-50N 102-58E…
Seismic survey works by M/V pxgeo 2 towing eight cables, each 5 mile long → - HYDROPAC 2241/26 · Surveys · Timor Sea2026-08-05 · in force
TIMOR SEA. AUSTRALIA. SURVEY OPERATIONS IN PROGRESS UNTIL FURTHER NOTICEBY M/V SW BLY TOWING TWELVE 7300 METER CABLES IN AREA BOUND BY 12-47.76S 127-35.15E, 12-38.08S 127-44.03E, 12-38.27S 128-06.05E,…
Survey operations in progress until further noticeby M/V sw bly towing twelve 7300 meter cables in area… →
How it reads in recent messages
- HYDROLANT 1825/26 · Surveys · North Atlantic Ocean2026-09-15
…IN PROGRESS UNTIL 26 SEP BY M/V AMAZON WARRIOR, M/V VENTURE G AND M/V BIG JOHN VII TOWING 12 10000 METER LONG CABLES IN AREA BOUND BY 04-33.71N 050-01.26W, 05-42.36N 048-58.13W, 03-02.99N 046-18.20W,…
Survey operations in progress until 26 sep by M/V amazon warrior, M/V venture g and M/V big john VII towing… → - HYDROLANT 1774/26 · Surveys · North Atlantic Ocean2026-09-07
…IN PROGRESS UNTIL 19 SEP BY M/V AMAZON WARRIOR, M/V VENTURE G AND M/V BIG JOHN VII TOWING 12 10000 METER LONG CABLES IN AREA BOUND BY 04-33.71N 050-01.26W, 05-42.36N 048-58.13W, 03-02.99N 046-18.20W,…
Survey operations in progress until 19 sep by M/V amazon warrior, M/V venture g and M/V big john VII towing… → - HYDROLANT 1770/26 · Surveys · North Sea2026-09-06
…SEA. NORWAY. 1. SURVEY OPERATIONS IN PROGRESS UNTIL FURTHER NOTICE BY M/V RAMFORM ATLAS TOWING 12 7050 METER LONG CABLES IN AREA BOUND BY 61-21.60N 002-40.30E, 61-24.60N 003-02.00E, 60-22.70N 003-40.00E,…
Survey operations in progress until further notice by M/V ramform atlas towing 12 7050 meter long cables in… → - HYDROLANT 1735/26 · Surveys · North Sea2026-09-02
…SEA. NORWAY. SURVEY OPERATIONS IN PROGRESS UNTIL FURTHER NOTICE BY M/V RAMFORM ATLAS TOWING 15 7050 METER LONG CABLES IN AREA BOUND BY 56-59.50N 002-56.70E, 57-30.00N 004-51.30E, 56-48.70N 005-26.00E,…
Survey operations in progress until further notice by M/V ramform atlas towing 15 7050 meter long cables in… → - NAVAREA 19 106/26 · Cable ops · Norwegian Sea2026-08-28
NORWEGIAN SEA. SEISMIC SURVEY IN PROGRESS BY M/V AMAZON CONQUEROR TOWING 12 X 10000 METRE LONG CABLES IN AREA BOUND BY: A: 64-33.50N 006-04.80E B: 64-32.70N 004-33.70E C: 65-40.80N…
Seismic survey in progress by M/V amazon conqueror towing 12 X 10000 metre long cables in area bound by: a:… → - HYDROLANT 1691/26 · Surveys · Norwegian Sea2026-08-28
…SEA. 1. SURVEY OPERATIONS IN PROGRESS UNTIL FURTHER NOTICE BY M/V AMAZON CONQUEROR TOWING 12 10000 METER LONG CABLES IN AREA BOUND BY 65-40.80N 005-19.70E, 65-42.20N 006-52.30E, 64-33.50N 006-04.80E,…
Survey operations in progress until further notice by M/V amazon conqueror towing 12 10000 meter long cables… → - HYDROLANT 1663/26 · Surveys · South Atlantic Ocean2026-08-24
…ANGOLA. 1. SURVEY OPERATIONS IN PROGRESS UNTIL FURTHER NOTICE BY M/V RAMFORM VICTORY TOWING 12 THREE MILE LONG CABLES IN AREA BOUND BY 06-07.30S 011-14.00E, 06-31.10S 011-17.40E, 06-35.00S 010-51.00E,…
Survey operations in progress until further notice by M/V ramform victory towing 12 three mile long cables… →
Earliest in the archive
- NOAAORR-9022 · Spills · North Pacific Ocean1985-02-25
…slick sighted ~ 1/4 mile offshore of Pt. Reyes about 300 yds x 300 yds w pancakes 1sqft. Streamers from the northern most point of 2 slicks extending 2-3 miles, 1 ft wide, about 2-3 miles…
Point reyes, ca →
Often in the same message
Related terms
- Seismic survey
- A survey that maps the rock beneath the seabed with sound pulses from air guns, recorded on streamers kilometres long.
- Survey operations
- A research or survey vessel is mapping the seabed or water column, often while towing equipment.
- Tow / towing
- A vessel towing another vessel, a barge or a structure — slow, hard to manoeuvre, and with a long line between.
- Restricted in ability to manoeuvre
- A vessel whose work — cable laying, diving, dredging, towing — stops it from keeping out of other ships' way.
Warning types that use it
Counts cover the messages in this archive that use the term, recounted 2026-09-24; see coverage for what is collected and since when. Not for navigation — follow official NAVAREA and coastal broadcasts.