FRENCH MULTI-COASTAL MARITIME LOGISTICS EXPERTISE
Atlantic Coast
Channel Coast
Offshore
TETIS & ISMER – Reliable Experts
in Offshore Wind and Tidal Energy
Covering the Entire Atlantic and Channel Coastlines
With TETIS headquartered in Le Havre (Normandy) and ISMER based in Lorient (Brittany), our combined expertise in marine and subsea operations powers the development of offshore wind and tidal energy across France.
Operating along the full Atlantic coastline and throughout the English Channel, our experienced teams of commercial divers and marine surveyors deliver turnkey solutions for the installation, inspection, and maintenance of offshore wind farms — always with a strong commitment to safety and environmental stewardship.
In addition to offshore services, TETIS & ISMER are trusted specialists in nearshore and port operations. From inland waterways to the open sea, in shallow zones or depths reaching 50 meters, we provide tailored, high-performance solutions to meet your most complex subsea challenges.
Main Location
At the Heart of France’s
Offshore Wind Development Network
With key operational sites in Le Havre, Lorient, Saint-Nazaire, and Saint-Malo, TETIS & ISMER are strategically positioned within France’s rapidly growing offshore wind ecosystem. Each location is equipped with office space and integrated logistics infrastructure.
Our presence extends to the ports of Calais, Brest, Paris, and Saint-Nazaire, with administrative headquarters based in La Roche-sur-Yon.
Brest, Lorient, and Saint-Nazaire are recognized hubs for Marine Renewable Energy (MRE), playing vital roles in the installation and maintenance of offshore wind farms along the Brittany-Atlantic coastline.
Le Havre, France’s primary Channel port, is ideally situated near the wind farms of Courseulles, Fécamp, and Dieppe. Its central location supports seamless operations from Cherbourg to the Belgian border.
Marine Renewable Energies
A Long-Term Commitment to Marine Renewables
TETIS & ISMER are deeply invested in supporting France’s marine energy transition. By partnering with leading structural, oceanographic, and environmental engineers, we deliver innovative, sustainable solutions for offshore wind infrastructure.
With dedicated bases and advanced capabilities, we are actively involved in the long-term development of offshore wind. In Lorient, our site offers a full-service logistics platform for offshore maintenance — complete with secure equipment storage, a loading dock, and flexible workspace for temporary offices — making it an ideal operational base.
We operate in compliance with IMCA standards and are committed to transparent, high-quality operations in both French and international waters.
Backed by dedicated logistics, intervention vessels, and 24/7 remote monitoring, TETIS & ISMER are fully equipped to lead in offshore wind farm maintenance.
Looking for a trusted marine renewables partner? Your solution starts here.
Lorient, Le Havre
Port Infrastructure – Lorient
Lorient: A Strategic Base for Offshore Support
- A naturally sheltered bay with unrestricted access to open water and no height limitations — ensuring year-round operations
- A dedicated 1.5-hectare TETIS & ISMER maintenance base, with 100 meters of quayside and full crew support for offshore service vessels
- A specialized ship repair zone with a 650-ton ship lift and an 80-meter repair quay
Working in synergy with the EMR terminal in Brest, Lorient is part of a complementary port ecosystem that supports France’s offshore wind expansion. This positioning places TETIS & ISMER at the center of activity for the country’s seven offshore wind farms — totaling 6 GW of installed capacity — and ready to support future floating wind developments.
Port Infrastructure – Le Havre
Le Havre’s port infrastructure provides:
- A highly protected area within the maritime-river zone, located behind the locks. Thanks to a privileged partnership with the port authority, Le Havre: Gateway to the Channel and Beyond
- A secure, inland maritime-river zone located behind locks, with privileged port access for additional storage, mooring, and quayside areas
- A 1.5-hectare dedicated TETIS base with 120 meters of quayside, ideal for shallow-draft vessels
- Access to the “Eure” dry docks — three docks located in the tidal basin and available 24/7, accommodating vessels up to 180 meters in length
- Additional quays for afloat repairs
- Le Havre boasts strong maritime and road links to other strategic ports — including Caen-Ouistreham, Dieppe, and Fécamp — all future homes to offshore wind maintenance bases.
TETIS & ISMER
TETIS & ISMER – Navigating the Future of Marine Energy
TETIS & ISMER provide complete lifecycle services for underwater marine energy devices, including:
- Tidal turbines
- Wave energy converters
- Fixed and floating offshore wind turbines
With operations aligned to IMCA standards and progressing toward full certification, we are well-positioned to lead international projects.
Our bases offer extensive storage and modular office space. Equipped with specialized diving vessels and inspection tools, we ensure reliable maintenance and seamless interventions across all marine energy systems.
Survey
Smart Survey Solutions for Smart Marine Infrastructure
We offer a full range of survey and monitoring services:
- Mooring and corrosion inspections
- Emergency response for fishing gear, buoys, and lines
- Maintenance of offshore substations and subsea structures
- Subsea cable and junction box inspections
- Landfall and transition zone surveys
To enhance our capabilities, we deploy lightweight ROVs with acoustic cameras and precision positioning systems.
We also perform bio-acoustic monitoring in collaboration with leading research institutions, meeting the most rigorous scientific standards.
Environmental stewardship is central to our approach — because “the ocean starts at our worksites.”
About us
TETIS & ISMER – Over 30 Years Beneath the Surface
Headquartered in Lorient — inside a historic submarine base on the Scorff River — TETIS & ISMER combine deep local roots with decades of underwater expertise in maritime and inland infrastructure.
With a strategic base in Le Havre, France’s leading logistics hub, TETIS offers responsive support to offshore operators in the Baie de Seine and along the Opal Coast. Our Normandy teams are ready to deploy within hours for emergency or high-risk interventions.
Driven by a commitment to service, technical excellence, and innovation, we merge hands-on experience with engineering know-how and creative problem-solving.
Certified in hyperbaric operations and a proud member of SNETI, our professional divers operate confidently down to 50 meters.
As we expand into Marine Renewable Energies, we offer a full suite of services — from wind turbine installation to cable burial and tidal turbine deployment. Our engineering team is ready to study your needs and deliver tailored solutions.
Customers
Trusted by Industry Leaders
At TETIS & ISMER, continuous service improvement is a priority. We are proud to be a trusted partner for public authorities, industrial clients, and major commercial ports.
Scope of Services
Scope of Services
Need It Done? Just Ask.
We’ve played a key role in the development of the SEMREV test site, especially in cable and hub installations.
Our services include:
- Bathymetric and sonar surveys, ROV inspections
- Subsea inspections and technical assessments
- Geotechnical sampling and sediment analysis
- Biodiversity evaluations
- Underwater maintenance and repairs
- Interventions on mooring lines and subsea cables
- Disconnecting and reconnecting subsea equipment
We operate across:
- Fixed and floating wind farms
- River and marine tidal turbines
- Wave energy systems
- Cable laying and trenching operations
- Subsea structures (hubs, substations, etc.)
- Rock and debris removal
- Foundation and anchoring systems
- Structural works and engineering support via ETPO Group
Equipment
Equipped for Excellence
TETIS & ISMER follow rigorous equipment management practices to ensure operational success. Our inventory is modern, certified, and adapted for each mission, with full engineering validation.
Our logistics bases in La Roche-sur-Yon, Lorient, and Le Havre guarantee quick response and spare part availability.
Our resources include:
- Work barges from 5 to 700 tons
- Cranes from 1 to 250 tons
- Equipment rated to 50 meters depth
- Offshore tenders and diving support vessels (up to 20 NM)
- Pollution control kits and robotic tools
- Lightweight ROVs, dual-frequency sonar, acoustic imaging
We collaborate with major maritime players such as TSM, Jifmar, SeaOwl, and Abeilles International, while maintaining strong partnerships with local marine service providers along both coasts.
Certifications
Certifications
- Member of SNETI (National Union of Underwater Contractors)
- Certified for Hyperbaric Operations under French regulations
- Approved Bureau Veritas supplier for underwater inspections
Scuba
TETIS & ISMER Divers – Precision at Depth
Ready to dive into your next challenge? Our expert dive teams operate with unmatched precision — safely reaching depths of 50 meters.
Certified to French hyperbaric standards (Mention A & B) and trained to IMCA protocols, we are equipped for both domestic and international offshore missions.
At TETIS & ISMER, safety is not just a policy — it’s a culture. With cutting-edge tools and deep regional knowledge, we deliver efficient, high-quality marine services from the Atlantic to the Channel.
Dive deeper with us. Experience the difference — below the surface.
Contact
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To discuss your project or request more information, call us at +33 6 51 97 22 89 or use the contact form below.
We’ll respond promptly — thank you!
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