Marine Works
Between 2025 and 2035, the construction of the Sizewell C Nuclear Power Station will comprise various marine elements. A permanent Beach Landing Facility, will be constructed to facilitate the delivery of various materials and components by water, rather than by rail or road.
A temporary jetty called a Marine Bulk Import Facility is also proposed, which will allow large north sea barges to berth up close to the site to off-load aggregate. There will also be a variety of intake and outfall tunnels built in the harbour below the seabed to provide water to the nuclear plant.
The proposed marine components are shown in the image below:
Marine Works Programme
There will be extensive activity within the harbour from September 2025 onwards. The programme below shows the indicative start and end points of marine works up until the end of 2027.
| Sizewell C Marine Works Programme | ||
| Type | Activity |
2025
Q3
Q4
2026
Q1
Q2
Q3
Q4
2027
Q1
Q2
Q3
Q4
|
|---|---|---|
| Temporary Sea Defence | Piling |
July
August
September
October
November
December
January
February
March
April
May
June
July
August
September
October
November
December
January
February
March
April
May
June
July
August
September
October
November
December
|
| Combined Drainage Outfall | Dredge, pipe install, head structure |
July
August
September
October
November
December
January
February
March
April
May
June
July
August
September
October
November
December
January
February
March
April
May
June
July
August
September
October
November
December
|
| Desalination Pipeline | Dredge, pipe install, head structure |
July
August
September
October
November
December
January
February
March
April
May
June
July
August
September
October
November
December
January
February
March
April
May
June
July
August
September
October
November
December
|
| Marine Bulk Import Facility | Dredge, piling, platform, fenders |
July
August
September
October
November
December
January
February
March
April
May
June
July
August
September
October
November
December
January
February
March
April
May
June
July
August
September
October
November
December
|
| Beach Landing Facility | Dredge, piling, platform, fenders |
July
August
September
October
November
December
January
February
March
April
May
June
July
August
September
October
November
December
January
February
March
April
May
June
July
August
September
October
November
December
|
| Marine Bulk Import Facility | Aggregate Deliveries |
July
August
September
October
November
December
January
February
March
April
May
June
July
August
September
October
November
December
January
February
March
April
May
June
July
August
September
October
November
December
|
Marine Spatial Planning
At the peak of marine activity in 2029, it is currently estimated that there could be over 1300 vessel movements per month, or over 40 per day. This includes a range of large construction vessels, delivery vessels, small project vessels (survey boats and crew transfer vessels) and port/service vessels (such as pilot boats, or patrol launches).
Therefore, during the construction phase, there may be times when parts of the harbour are closed to the public for safety reasons. Information will be updated here if and when this should occur.
Marine Construction Zone
To ensure the safety of mariners during a period of more intense construction activity, a Marine Construction Zone (MCZ) has been established to accommodate a number of marine construction and associated service vessels engaged in construction activities for the Sizewell C Nuclear Power Station. All vessels other than those engaged in the construction works are excluded from this area on the grounds of navigational safety until the MCZ is removed.
The MCZ was formally established on 1st February 2026 for an initial 12-month period. This may be extended at the discretion of the Harbour Master, subject to an ongoing review of Sizewell C construction programme. The coordinates of the MCZ are as follows:
| Latitude | Longitude |
| 52° 12.9171′ N | 001° 37.4473′ E |
| 52° 13.4574′ N | 001° 37.5149′ E |
| 52° 13.4655′ N | 001° 38.2073′ E |
| 52° 12.9263′ N | 001° 38.2270′ E |
The seaward extents of the MCZ are marked by two special mark buoys, light characteristics Fl Y 5s and are positioned at the following coordinates. For further information, see Notice to Mariners 7 of 2026.
| Latitude | Longitude |
| 52° 13.4655′ N | 001° 38.2073′ E |
| 52° 12.9263′ N | 001° 38.2270′ E |
SZC SHA Marine Construction Zone outlined in red.
Marine Fishing & Recreation Zone (MFRZ)
A Marine Fishing & Recreation Zone (MFRZ) was established within Sizewell C Harbour in late August 2025. This area of the harbour is designated for the use of leisure vessel owners, leisure fishermen and other recreational users of the harbour waters. Commercial, service and construction vessels are generally be excluded from this area except where unavoidable.
Mariners will be informed of any planned minor construction vessel works within the MFRZ in advance by Notice to Mariners. This zone has been established to allow leisure use of this section of the harbour safely, largely segregated from the construction activities underway elsewhere within the harbour.
Leisure users within the MFRZ are still subject to the General Directions of the harbour.
The MFRZ is currently in place until 10 March 2027 and may be further extended at the discretion of the Harbour Master, subject to an ongoing review of the Sizewell C construction programme.
The coordinates of the MFRZ are as follows:
| Latitude | Longitude |
| 52° 12.6742′ N | 001° 39.9994′ E |
| 52° 11.9981′ N | 001° 39.9967′ E |
| 52° 11.9979′ N | 001° 37.3296′ E |
| 52° 12.8096′ N | 001° 37.4392′ E |
| 52° 12.8209′ N | 001° 38.4366′ E |
SZC Marine Fishing & Recreation Zone.