North Sea

IHO sea area 4 · -4° to 12° E, 51° to 61° N

in force
3
last 12 months
3
since 1997
4,727
categories
11

In force now · 3

  1. HYDROLANT 1496/26 · Surveys2026-08-03
    Survey operations are underway in the North Sea near Norway by the vessel Ramform Hyperion towing ten 2740-meter cables, requesting a three-mile berth.
  2. HYDROLANT 1488/26 · Nav aids2026-08-01
    Medium frequency DSC and radiotelephone services are off air at Bawdsey, Cullercoats, and Gregness site. Hydrolant 1441/26 is cancelled.
  3. HYDROLANT 1477/26 · Surveys2026-07-31
    Survey operations are in progress in the North Sea off Norway, with vessel Amazon Conqueror towing eight 1609-meter cables; two-mile berth requested.

Longest in force

  1. HYDROLANT 1477/26 · Surveys2026-07-31
    Survey operations are in progress in the North Sea off Norway, with vessel Amazon Conqueror towing eight 1609-meter cables; two-mile berth requested.
  2. HYDROLANT 1488/26 · Nav aids2026-08-01
    Medium frequency DSC and radiotelephone services are off air at Bawdsey, Cullercoats, and Gregness site. Hydrolant 1441/26 is cancelled.
  3. HYDROLANT 1496/26 · Surveys2026-08-03
    Survey operations are underway in the North Sea near Norway by the vessel Ramform Hyperion towing ten 2740-meter cables, requesting a three-mile berth.

By year

97
98
99
00
01
02
03
04
05
06
07
08
09
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
26

By month (all years)

J
F
M
A
M
J
J
A
S
O
N
D

By category · since 1997

Nav aids2,50053%
Other66814%
Cable ops65814%
Surveys58212%
Wrecks1704%
Containers441%
Derelicts341%
Exercises321%
Debris291%
Mines90%
Missiles10%

Archive · 4,724 cancelled

  1. HYDROLANT 3000/18 · Other2018-09-22 → 2018-09-25
    All navigational aids inoperative at platforms: a. brigantine br, 53-26.5N 002-41.8E
  2. HYDROLANT 2999/18 · Other2018-09-22 → 2018-09-25
    All navigational aids inoperative at platforms: a. caravel, 53-25.8N 002-53.9E
  3. HYDROLANT 2998/18 · Nav aids2018-09-22 → 2018-09-22
    Flamborough head light 54-07N 000-05W unreliable
  4. HYDROLANT 2982/18 · Surveys2018-09-21 → 2018-10-14
    Survey operations in progress until further notice by M/V sanco swift towing 12 9000 meter long cables in…
  5. HYDROLANT 2973/18 · Surveys2018-09-20 → 2018-11-01
    Underwater operations in progress until further notice by M/V ocean vantage in area bound by 56-41N 001-57W,…
  6. HYDROLANT 2960/18 · Other2018-09-19 → 2018-10-31
    Unexploded ordnance in area bound by 52-05N 001-37E, 52-05N 001-45E, 51-58N 001-30E, 52-00N 001-30E
  7. HYDROLANT 2903/18 · Nav aids2018-09-14 → 2018-10-06
    Platform 48/7B-HOTON 53-48.2N 001-12.3E unlit
  8. HYDROLANT 2899/18 · Surveys2018-09-13 → 2018-09-20
    Underwater operations 140001Z to 200001Z sep in area within one mile of 56-09.8N 002-35.1W
  9. HYDROLANT 2833/18 · Nav aids2018-09-06 → 2018-10-18
    All navigational aids at platform 48/19B-A, 53-22.1N 001-39.2E inoperative
  10. HYDROLANT 2829/18 · Nav aids2018-09-05 → 2018-09-11
    All navigational aids at platform 49/26-D, 53-00.5N 002-11.1E inoperative
  11. HYDROLANT 2799/18 · Nav aids2018-09-02 → 2018-09-10
    All navigational aids at platform 48/20, 53-27.0N 001-53.1E inoperative
  12. HYDROLANT 2770/18 · Other2018-08-30 → 2018-08-31
    Unexploded ordnance marked by buoys in 51-44.27N 001-01.24E
  13. HYDROLANT 2768/18 · Nav aids2018-08-30 → 2018-09-01
    Platform 48/7B-HOTON, 53-48.2N 001-12.3E unlit
  14. HYDROLANT 2729/18 · Cable ops2018-08-27 → 2018-08-31
    Underwater operations in progress until further notice by cableship sovereign in vicinity of 52-21.2N…
  15. HYDROLANT 2728/18 · Nav aids2018-08-27 → 2018-10-05
    Fog signal at platform 12/21C jacky, 58-11.0N 002-58.8W inoperative
  16. HYDROLANT 2692/18 · Wrecks2018-08-23 → 2018-09-21
    Dangerous wrecks: a. least depth 13.1 meters in 51-43.51N 002-02.36E
  17. HYDROLANT 2681/18 · Cable ops2018-08-22 → 2018-08-27
    Underwater operations in progress until further notice by cableship sovereign in vicinity 52-21.4N 002-55.5E
  18. HYDROLANT 2633/18 · Cable ops2018-08-17 → 2018-09-28
    Cable operations in progress until further notice by cableship connector and M/V lange wrapper in area bound…
  19. HYDROLANT 2630/18 · Cable ops2018-08-17 → 2018-08-22
    Underwater operations in progress until further notice by cableship ile de sein and cableship ile daix with…
  20. HYDROLANT 2608/18 · Wrecks2018-08-15 → 2018-08-23
    Dangerous wreck in 51-43.08N 002-01.97E

Sea boundaries: Flanders Marine Institute (2018), IHO Sea Areas v3, marineregions.org (CC BY 4.0). Not for navigation — follow official NAVAREA / coastal broadcasts.