Seismic survey
A survey that maps the rock beneath the seabed with sound pulses from air guns, recorded on streamers kilometres long.
Seismic survey vessels tow an array of air guns and one or more streamers — cables of hydrophones — that can extend several kilometres astern, ending in a tail buoy. The whole spread turns slowly and cannot stop quickly, so warnings ask other ships to keep well clear, sometimes by several miles.
Seismic work is mostly associated with oil, gas and carbon-storage exploration, and with academic studies of the sea floor. Warnings often say how long the streamers are and how deep they are towed.
What the archive shows
11,441 messages in this archive use “Seismic survey”, the earliest issued 1983-12-07 and the latest 2026-08-29. 8 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 1,564 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 11,423 of 11,441 recorded messages (100%), the largest warning type group in this selection.
Located messages that use it fall in 72 sea areas; the most frequent are South Atlantic Ocean (4,861), North Atlantic Ocean (657) and Arabian Sea (296).
Its use is spread fairly evenly through the year: the busiest month, January, has 1,096 messages and the quietest, September, 844.
By warning series: HYDROLANT 8,019, HYDROPAC 2,744, NAVAREA IV 469 and HYDROARC 190, and 7 more.
Messages using it, by year of issue
By month of issue, all years
Where it appears · 72 sea areas
- South Atlantic Ocean 4,861
- North Atlantic Ocean 657
- Arabian Sea 296
- South China Sea 279
- Bay of Bengal 275
- Mediterranean Sea - Eastern Basin 240
- North Sea 224
- Gulf of Mexico 213
- Norwegian Sea 127
- Black Sea 112
- Persian Gulf 95
- Gulf of Guinea 92
In force now · 8
- NAVAREA 7 246/26 · Cable ops · South Atlantic Ocean2026-08-24 · in force
…NE SECTOR - OFFSHORE ORANGE 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…
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…
Seismic survey in progress by rsv amazon conqueror towing 8 X 1 mile long cables in area bound by 60-00.9N… → - 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.…
Seismic survey works by M/V pxgeo 2 towing eight cables, each 5 mile long → - AUSCOAST 266/26 · Cable ops · Timor Sea2026-08-05 · in force
SPECIAL PURPOSE VESSEL SW BLY / C6ZD3 / 311052800 CONDUCTING SEISMIC SURVEY TOWING TWELVE 4.5 NM CABLES IN AN AREA BOUNDED: 12-47.76S 127-35.15E 12-38.08S…
Special purpose vessel sw bly / C6ZD3 / 311052800 conducting seismic survey towing twelve 4.5 nm cables in… → - NAVAREA I 163/26 · Cable ops · North Sea2026-08-03 · in force
NORTH SEA. THE PATCH NORTHWESTWARDS. 1. SEISMIC SURVEY IN PROGRESS BY M/V RAMFORM HYPERION TOWING 10 X 1.7 MILE LONG CABLES IN AREA…
The patch northwestwards → - NAVAREA I 133/26 · Cable ops · Norwegian Sea2026-07-03 · in force
NORTH SEA. GULLFAKS OIL FIELD. SEISMIC SURVEY IN PROGRESS BY RSV RAMFORM ATLAS TOWING 17 X 3600 METRE LONG CABLES IN AREA BOUND…
Gullfaks oil field →
How it reads in recent messages
- 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…
Seismic survey in progress by M/V amazon conqueror towing 12 X 10000 metre long cables in area bound by: a:… → - NAVAREA II 269/26 · Cable ops · South Atlantic Ocean2026-07-02 · in force
POINTE NOIRE. SPECIAL OPERATIONS. SEISMIC SURVEY. IN PROGRESS UNTIL FURTHER NOTICE BY M/V RAMFORM VICTORY IN AREA BOUNDED BY:…
Special operations →
Earliest in the archive
- HYDROLANT 2251/83 · Cable ops1983-12-06
LEMAN GAS FIELD TO DEEP WATER ROUTE. SEISMIC SURVEY IN PROGRESS BY M/V GARDLINE LOCATOR WITHIN 3 MILES OF 53-04.0N. 02-32.5E. WIDE…
Seismic survey in progress by M/V gardline locator within 3 miles of 53-04.0N →
Often in the same message
Related terms
- Survey operations
- A research or survey vessel is mapping the seabed or water column, often while towing equipment.
- Towed array / streamer
- Equipment towed a long way behind a vessel — sonar, a hydrophone cable, a sampling sled — invisible at the surface.
- Wide berth requested
- Keep well clear — or, when a distance is given ("TWO MILE BERTH REQUESTED"), at least that far away.
Warning types that use it
- Surveys — Hydrographic and scientific survey vessels, often towing long arrays.
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.