Seajacks

Offshore Wind Installation Servicesseajacks.com

Seajacks operates self-propelled heavy-lift jack-up vessels that transport, install, and maintain offshore wind turbines and foundations for major wind farm developers and turbine OEMs across Europe, North America, and Asia Pacific.

Company typePublic
Founded2017
HeadquartersGreat Yarmouth, United Kingdom
Headcount251–500
GTM typeB2B
OfferingServices

What Seajacks does

Seajacks owns and operates self-propelled jack-up vessels used to install and maintain offshore wind farms worldwide. The firmographic record places Seajacks in Great Yarmouth, United Kingdom, with 251-500 employees and a founding year of 2006. The company is now part of the Cadeler group (Cadeler A/S, listed on Oslo Børs as CADLR), and the operational fleet spans heavy-lift installation vessels including Wind Osprey (1,600 metric ton crane capacity post-upgrade), Wind Orca, Wind Scylla, Wind Zaratan, Wind Peak, Wind Mover, and Nexra. Vessels can install turbines in water depths exceeding 55 meters (deepest installation recorded at 59 meters at Seagreen) and have achieved installation of an 11 MW turbine in under 24 hours at Hollandse Kust Zuid.

Seajacks/Cadeler generates revenue through three primary streams: Transport and Installation (T&I) services covering wind turbine generators, monopile foundations, and transition pieces; Operations & Maintenance (O&M) services including component exchanges, blade servicing, and gearbox replacements; and offshore accommodation services for substations and converter platforms. Pricing is project-based and contract-negotiated rather than published; engagements are multi-year and awarded directly to enterprise customers. The customer base consists of large offshore wind developers and turbine OEMs including Ørsted, RWE, Vattenfall, Siemens Gamesa, ScottishPower Renewables, TotalEnergies, SSE Renewables, Skyborn Renewables, EnBW, DEME Group, and OW Ocean Winds.

The go-to-market is sales-led, direct enterprise contracting with no channel intermediaries. Operationally, Seajacks/Cadeler has executed projects across Europe (UK, Germany, Netherlands, Denmark, Belgium, Ireland, Poland), North America (USA), and Asia Pacific (Taiwan, Japan). Capital intensity is the defining feature of the business: purpose-built vessels cost hundreds of millions each, creating high barriers to entry and concentrating the global competitive set among a small number of specialized operators. Recent strategic emphasis has been on fleet expansion (capacity doubling in 2025), crane upgrades to handle next-generation 14-15+ MW turbines, and geographic diversification into emerging offshore wind markets such as Poland.

Seajacks firmographics

Firmographics

Name: Seajacks
Legal name: Cadeler
Website: https://seajacks.com
Company type: Public
Founded year: 2017
Operating status: Operating
Headcount range: 251–500 employees
Short description: Seajacks operates self-propelled heavy-lift jack-up vessels that transport, install, and maintain offshore wind turbines and foundations for major wind farm developers and turbine OEMs across Europe, North America, and Asia Pacific.
Ownership category
akta.pro rank

Seajacks industry classification

Industry

Product category: Offshore Wind Installation Services
NAICS: Support Activities for Water Transportation (4883)
SIC: Water Transportation (4400)
akta.pro primary industry: Offshore Wind Power Generation (Fixed-Bottom) (EUACAFAB)
akta.pro secondary industries: Offshore Wind Substructures & Marine Engineering (Monopiles, Jackets, Floating) (EUAMACAE), Offshore Wind Power Generation (Floating) (EUACAFAC)

Keywords

Offshore wind installation
Jack-up vessel services
Wind turbine transport
Offshore foundation services
Marine installation services

Where Seajacks is headquartered

Location

Headquarters

HQ city: Great Yarmouth
HQ country: United Kingdom
HQ region: Europe

Offices6 records

Markets served

Seajacks business model

Business model

GTM type: B2B
Offering type: Services
Cost components: Operations, Personnel, Infrastructure, Marketing or Sales, Others

Revenue model

Transport and Installation (T&I) Services: Cadeler provides offshore wind turbine and foundation installation services via chartered vessels to wind farm developers and turbine manufacturers. Contracts are secured for specific projects with pricing based on scope of work, vessel deployment duration, and technical requirements.
Operations & Maintenance Services: Cadeler provides ongoing O&M services including turbine maintenance, main component exchanges, blade servicing, and gearbox replacements for installed offshore wind farms.
Accommodation Services: Vessels provide offshore accommodation support during construction and maintenance works on offshore substations and converter platforms.

Pricing tiers

Model	Billing	Price
Other	Multi-year contract	Project-based contracting

Go-to-market motion1 record

Distribution channels1 record

Marketing channels3 records

Seajacks product offering

Product offering

Core offering

Seajacks owns and operates self-propelled jack-up vessels that safely and efficiently install and maintain offshore wind farms worldwide. The company's fleet transports and installs wind turbine components, foundations, and substations, and supports maintenance and crew transfer operations for offshore wind developers.

Product overview

Cadeler operates a fleet of specialized jack-up offshore wind installation vessels providing integrated services for the offshore wind energy sector. The company offers wind turbine generator (WTG) installation, monopile foundation installation, operations and maintenance (O&M) services, and offshore accommodation support. Core vessels include Wind Osprey, Wind Orca, Wind Scylla, Wind Zaratan, Wind Mover, and Nexra. Services span transportation and installation (T&I) of turbines and foundations, maintenance campaigns, and vessel chartering to major offshore wind developers worldwide.

Differentiator

Problem solved

Functional benefit

Products and services

Self-propelled jack-up vessel charter and offshore wind farm installation services

Quantifiable outcome

World's largest single offshore wind farm (1.5 GW) installed at Hollandse Kust Zuid
+5 more outcomes

Companies that use Seajacks

Customer profile

Named customers11 records

Segments1 record

Ideal customer profiles1 record

Seajacks technology and API

Technology

Technology focussed No

API detail

Has API: No
API docs
API detail

Core technology

AI maturity

App detail

Feature3 records

Seajacks partnerships and signals

Strategic signal

Partnerships

Two partnerships are on record, tiered minor.

Jan De Nul GroupminorOthers · 9 April 2026Mentioned as a key player in the Offshore Wind Turbine Installation Vessel Market in a market analysis report by Worldwide Market Reports. Both Jan De Nul Group and Cadeler operate in the same sector of specialized offshore wind installation vessels.
DEME GroupminorOthers · 9 April 2026Mentioned as a key player in the Offshore Wind Turbine Installation Vessel Market in a market analysis report. DEME Group and Cadeler are both major operators in the offshore wind installation vessel market segment.

Scale indicators8 records

Recent moves6 records

Expansion highlights6 records

Seajacks competitors and assessment

Company assessment

Direct peers

DEME Group: Belgian marine contractor operating offshore wind installation vessels (e.g., Apollo, Thor) and competing head-to-head with Cadeler for major European T&I contracts.
Jan De Nul Group: Belgian/Luxembourg marine contractor with the Voltaire and other heavy-lift jack-up vessels competing directly in the offshore wind installation market.
Van Oord: Dutch marine contractor operating WTIVs such as Aeolus and Boreas for offshore wind foundation and turbine installation across European markets.
Seaway 7: Subsea 7's dedicated offshore wind business, operating heavy-lift vessels for turbine and foundation installation; a direct competitor in the European and US WTIV market.
Heerema Marine Contractors: Dutch offshore installation contractor with heavy-lift crane vessels (e.g., Aegir, Thialf) that increasingly compete in offshore wind foundation and turbine installation.
Saipem: Italian offshore engineering and construction company with heavy-lift and wind installation vessels serving the offshore wind and oil & gas markets.
Boskalis: Dutch marine services group with growing offshore wind installation capabilities, including seabed preparation and foundation installation work overlapping with Cadeler's scope.
Penta-Ocean Construction: Japanese marine and offshore construction contractor with growing involvement in offshore wind installation projects, particularly in the Asia-Pacific market where Cadeler also operates.

Emerging players

Havfram: Norwegian offshore wind installation vessel pure-play with newbuild WTIVs targeting the same European and US markets as Cadeler.

Regional players

ZPMC: Chinese heavy equipment manufacturer and vessel operator; a regional player in offshore wind installation vessels with growing presence in Asia-Pacific projects that overlap geographically with Cadeler's Taiwan and Japan footprint.

Market position

Strengths5 records

Weaknesses5 records

Competitive moat5 records

Key risks6 records

Key highlights7 records

Customer concentration

Seajacks financial estimates

Financial estimate

Revenue estimate

Valuation estimate

Seajacks leadership team

Management profile

Number of profiles

Profiles3 records

Seajacks funding detail

Funding detail

Funding overview

Funding rounds1 record

Investors1 record

Funding detail is available on the Subscription and Enterprise plan.Contact sales →

Seajacks M&A and investment

M&A and investment

M&A

Investments

M&A and investment is available on the Subscription and Enterprise plan.Contact sales →

Frequently asked questions about Seajacks

What does Seajacks do?

Is Seajacks a public or private company?

Seajacks is a public company. It is classified as venture growth investor backed and is currently operating.

When was Seajacks founded?

Seajacks was founded in 2017. It employs 251 to 500 people.

Where is Seajacks based?

Seajacks is headquartered in Great Yarmouth, United Kingdom, in the Europe region.

How does Seajacks make money?

Three revenue lines are on record. Transport and Installation (T&I) Services are the primary driver. The others are operations & Maintenance Services and accommodation Services.

Who are Seajacks's main competitors?

Direct peers on record are DEME Group, Jan De Nul Group, Van Oord, Seaway 7, Heerema Marine Contractors, Saipem, Boskalis and Penta-Ocean Construction. Havfram is listed as an emerging player. ZPMC is listed as a regional player.

Does Seajacks have an API?

No public API is recorded for Seajacks.

What industry is Seajacks in?

Seajacks's product category is Offshore Wind Installation Services. Its primary akta.pro industry code is EUACAFAB, Offshore Wind Power Generation (Fixed-Bottom), with a secondary code of EUAMACAE, Offshore Wind Substructures & Marine Engineering (Monopiles, Jackets, Floating). Its NAICS code is 4883 and its SIC code is 4400.