Drilling rig / MODU
Also written: MODU, jack-up
A mobile offshore drilling unit — jack-up, semi-submersible or drillship — has moved into position, with anchors and a safety zone around it.
Mobile offshore drilling units move between well sites, and each move is broadcast so the new position can be avoided. The warning gives the rig's name and position, and often the radius of its anchor spread or the safety zone around it; under the UN Convention on the Law of the Sea, safety zones around offshore installations may extend up to 500 metres.
A semi-submersible rig can hold position on anchors laid far from the hull, so the danger extends well beyond the structure itself. When the rig leaves, a new warning cancels the old position.
What the archive shows
220 messages in this archive use “Drilling rig / MODU”, the earliest issued 1977-04-22 and the latest 2026-09-18. 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 2021, with 46 messages. Collection is incomplete between 2024-05 and 2026-08-17, so 2024, 2025 and 2026 are not comparable with fully collected years.
Surveys accounts for 181 of 220 recorded messages (82%), the largest warning type group in this selection.
Located messages that use it fall in 17 sea areas; the most frequent are Caribbean Sea (94), Gulf of Mexico (62) and North Atlantic Ocean (20).
Messages that use it are issued most often in September (25 across all years) and least often in January (12).
By warning series: NAVAREA IV 148, NOAAORR 37, HYDROPAC 14 and NAVAREA III 11, and 4 more.
Messages using it, by year of issue
By month of issue, all years
Where it appears · 17 sea areas
In force now · 8
- NAVAREA IV 898/26 · Surveys · Caribbean Sea2026-09-17 · in force
1. NAVAREA IV MOBILE OFFSHORE DRILLING UNITS POSITIONS AT 171600Z SEP: A. AGOSTO 12 19-23.0N 092-03.1W. B. ARGOS PLATFORM 27-10.4N…
NAVAREA IV mobile offshore drilling units positions at 171600Z sep: a. agosto 12 19-23.0N 092-03.1W → - NAVAREA III 139/26 · Surveys · Black Sea2026-09-12 · in force
BLACK SEA. 1- DRILLING OPERATIONS BY YILDIRIM RIG (IMO 9705469, MMSI 271053959), SUPPORTED BY ERTUGRUL BEY, AYBUKE,…
1- drilling operations by yildirim rig (imo 9705469, mmsi 271053959), supported by ertugrul bey, aybuke,… → - NAVAREA II 316/26 · Surveys · Gulf of Guinea2026-09-04 · in force
…POINTE NOIRE, SIERRA LEONE. RIG LIST. LAST KNOWN POSITIONS OF MOBILE OIL RIGS AND DRILL SHIPS AT 040430 UTC SEP 26. TO REPORT A MOBILE OFFSHORE DRILLING UNIT AS PER IMO RESOLUTION…
Last known positions of mobile oil rigs and drill ships at 040430 UTC sep 26 → - NAVAREA III 132/26 · Surveys · Black Sea2026-09-03 · in force
BLACK SEA. 1.- DRILLING OPERATIONS BY FATIH PLATFORM (IMO 9503770. MMSI 271046008), SUPPORTED BY OSMAN BEY, AYBUKE, FLORYA,…
Drilling operations by fatih platform (imo 9503770 → - NAVAREA III 128/26 · Surveys · Black Sea2026-08-27 · in force
BLACK SEA. 1.- DRILLING OPERATIONS BY YAVUZ RIG (IMO 9503768, MMSI 271046765) SUPPORTED BY OSMAN BEY, AYBUKE, FLORYA,…
Drilling operations by yavuz rig (imo 9503768, mmsi 271046765) supported by osman bey, aybuke, florya,… → - NAVAREA III 122/26 · Surveys · Black Sea2026-08-17 · in force
BLACK SEA. 1- DRILLING OPERATIONS BY ABDULHAMID HAN RIG (IMO 9705093. MMSI 271050408), SUPPORTED BY OSMAN BEY,AYBUKE,…
1- drilling operations by abdulhamid han rig (imo 9705093 →
How it reads in recent messages
- NAVAREA IV 872/26 · Surveys · Caribbean Sea2026-09-10
1. NAVAREA IV MOBILE OFFSHORE DRILLING UNITS POSITIONS AT 101400Z SEP: A. AGOSTO 12 19-23.0N 092-03.1W. B. ARGOS PLATFORM 27-10.4N…
NAVAREA IV mobile offshore drilling units positions at 101400Z sep: a. agosto 12 19-23.0N 092-03.1W → - NAVAREA IV 848/26 · Surveys · Caribbean Sea2026-09-02
1. NAVAREA IV MOBILE OFFSHORE DRILLING UNITS POSITIONS AT 021645Z SEP: A. AGOSTO 12 19-23.0N 092-03.1W. B. ARGOS PLATFORM 27-10.4N…
NAVAREA IV mobile offshore drilling units positions at 021645Z sep: a. agosto 12 19-23.0N 092-03.1W → - NAVAREA II 308/26 · Surveys · Gulf of Guinea2026-08-25
GULF OF GUINEA. OFFSHORE STRUCTURES. OFFSHORE RIGS PLATFORM CHG. MODU VALARIS RENAISSANCE 04-56.47N 004-30.37W WIDE BERTH REQUESTED
Offshore rigs platform chg →
Earliest in the archive
- NOAAORR-6237 · Spills · North Sea1977-04-22
…mixture composed of oil and mud spurted up to 180 feet into the air above the offshore drilling rig. The "blowout preventer" had apparently been placed upside down on the wellhead during…
Norway, north sea →
Often in the same message
Related terms
- Safety zone / exclusion zone
- An area ships must stay out of, or may only enter with permission, for safety or security.
- Wide berth requested
- Keep well clear — or, when a distance is given ("TWO MILE BERTH REQUESTED"), at least that far away.
- Offshore wind farm
- Construction or maintenance at an offshore wind farm: turbine foundations, jack-up vessels and export cables.
Warning types that use it
- Structures — Platforms, wind turbines and fish farms established, under construction or removed.
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.