Tetis

What Tetis does

Tetis is a French specialized underwater and maritime construction services company founded in 1994 and headquartered in Bellevigny (Vendée), operating as a subsidiary of Groupe ETPO. The company delivers subaquatic, confined-space, maritime, and fluvial works across four regional offices in Bellevigny, Lorient, Le Havre, and Paris, covering the French Atlantic coast, Channel coast, and inland waterway networks including the Loire, Cher, and Seine. Service lines span three core divisions: Travaux Subaquatiques (underwater work), Travaux Confinés (confined space work), and Travaux Maritimes Fluviaux (maritime and river work), with specialized offerings in ROV operations, non-destructive testing, underwater welding and cutting, salvage and heavy lifting, masonry rehabilitation, and marine renewable energy installations.

The company operates a project-based professional services model, generating revenue through direct contracts, public tender responses, and subcontracting arrangements with major French construction groups (Spie Batignolles, Bouygues TP, Charier GC, Freyssinet, ETPO). Customers include port authorities (Grand Port Maritime du Havre, Nantes Saint-Nazaire, Dunkerque; Port Atlantique La Rochelle), energy operators (EDF, Elengy/Engie, Total Raffinerie de Donges), regional governments (Région Bretagne, Département de Vendée), water utilities (Vendée Eau, SAUR, Veolia Eau), and defense entities (ESID de Brest). Technical capabilities include transportable hyperbaric chambers, ROVs with sonar and acoustic imaging capable of 300m depth operations, heavy lifting equipment up to 400+ tonnes, and access to ETPO Group's 500-tonne cranes and large barges.

Tetis maintains certifications including Entreprise Hyperbare (Qualianor, December 2019), Bureau Veritas diving team approval, MASE, ISO 9001/14001, and OHSAS 18001 (under ETPO Group), alongside FNTP professional cards. The company employs a team of certified Scaphandrier Classe 2 Mention A divers with multi-specializations (welding, rope access, NDT, corrosion). Marketing channels include NAVEXPO trade show presence, LinkedIn, YouTube, and earned media in regional and industry press. Revenue, funding, and ownership details are not publicly disclosed.

Name

Tetis

Legal name

T.E.T.I.S

Website

https://tetis.fr

Company type

Private

Founded year

1994

Operating status

Operating

Headcount range

11–50 employees

Short description

Tetis is a French underwater and maritime construction services company founded in 1994 and subsidiary of Groupe ETPO, delivering subaquatic, confined-space, maritime, and fluvial works to port authorities, energy operators, government, and water utilities across France.

Ownership category

akta.pro rank

Product category

Underwater Civil Engineering Services

NAICS

Ship Building and Repairing (336611), Architectural, Engineering, and Related Services (5413), Environmental Consulting Services (541620), Commercial and Industrial Machinery and Equipment (except Automotive and Electronic) Repair and Maintenance (8113), Ship and Boat Building (3366)

SIC

Ship & Boat Building & Repairing (3730), Construction - Special Trade Contractors (1700), Hazardous Waste Management (4955)

akta.pro primary industry

Emergency Towage & Rescue (Refloating, Grounding Response) (IMAJANAB)

akta.pro secondary industries

Underwater Hull Inspection, Cleaning & Propeller Services (TLAKAKAJ), Salvage Engineering, Surveying & Claims Support (IMAJANAH), Offshore Barge & Tender Assist Vessel Construction (IMAJACAH), Salvage Engineering, Surveying & Claims Support (Naval Architecture, Tow Plans) (TLAHAIAJ), Pollution Response & Environmental Salvage (Oil Spill, HAZMAT) (IMAJANAF)

Keywords

• Underwater construction services
• Maritime civil works
• Port infrastructure maintenance
• Confined space services
• Subaquatic engineering

Headquarters

HQ city

Belleville-sur-vie

HQ country

France

HQ region

Europe

Offices4 records

Markets served

GTM type

B2B

Offering type

Services

Cost components

Personnel, Operations, Infrastructure, Technology or R&D, Marketing or Sales

Revenue model

1. Subaquatic and Underwater Works Services: Project-based professional services for underwater construction, repair, inspection, and maintenance including marine, river, and port infrastructure work. Revenue generated through direct contracts with port authorities, government entities, and industrial operators.
2. Maritime and Fluvial Works: Specialized construction and maintenance services for maritime and fluvial infrastructure including quays, docks, locks, and navigational structures

Pricing tiers

Go-to-market motion1 record

Distribution channels3 records

Marketing channels4 records

Core offering

Tetis is a French marine and fluvial works company specializing in underwater (subaquatic) construction, inspection, and confined-space interventions. Founded in 1994 and headquartered in Saint-Herblain, the firm delivers services such as underwater inspection, welding, cutting, heavy lifting/salvage, rehabilitation of masonry works, and support for marine renewable energy projects, primarily for ports, public authorities, energy operators, and industrial clients.

Product overview

Tetis is a specialized underwater and maritime construction services company with 30 years of experience. The company operates a multi-service portfolio organized around three core divisions: Travaux Subaquatiques (Underwater Work), Travaux Confinés (Confined Space Work), and Travaux Maritimes Fluviaux (Maritime and River Work). Underwater services include ROV operations, inspection/expertise, welding/cutting, masonry rehabilitation, and marine renewable energy installations. Maritime and river services encompass port construction, dredging, mooring, and gate/sluice work. Confined space services cover treatment stations and ATEX zones. The company also operates an integrated study office and maintains certifications in hyperbaric operations.

Differentiator

Problem solved

Functional benefit

Products and services

• Travaux Subaquatiques (Underwater Works) Specialized underwater interventions for maritime, fluvial, port, and industrial structures, including inspection, repair, welding, cutting, and rehabilitation executed by Class A and Class C certified divers. Targeted at port authorities, public works owners, and industrial operators.
• Travaux Confinés (Confined-Space Works) Confined-space interventions carried out using certified divers and a transportable hyperbaric chamber to support safe execution of works in enclosed or pressurized environments such as tunnels, caissons, and industrial vessels.
• Travaux Maritimes, Fluviaux et Portuaires (Marine, River, and Port Works) Civil works on maritime, fluvial, and port infrastructure including quay walls, locks, dams, jetties, and harbor structures for public and private owners.
• Inspection et Expertise (Inspection and Expertise) Subaquatic inspection, diagnosis, and expert assessment of maritime, fluvial, port, and industrial structures using certified divers and ROVs to support asset integrity and maintenance planning.
• Soudure et Découpage (Welding and Cutting) Underwater welding and cutting services for repair, modification, and decommissioning of metallic maritime and port structures, performed by specialist diver-welders.
• Renflouage et Levage (Salvage and Lifting) Subaquatic salvage and heavy lifting of submerged objects, vessels, and structural elements using specialized hydraulic and mechanical equipment deployed by divers.
• Réparation et Réhabilitation d'Ouvrages Maçonnés (Masonry Repair and Rehabilitation) Underwater repair and rehabilitation of masonry structures such as quay walls, lock chambers, and historic port assets, including grouting, sealing, and structural restoration.
• Inspection par ROV (ROV Inspection) Remotely Operated Vehicle (ROV) based underwater inspection and visual assessment for structures where diver access is limited, unsafe, or inefficient.
• Énergies Marines Renouvelables (Marine Renewable Energy Support) Underwater and confined-space support services for marine renewable energy projects, including subsea installation, inspection, and maintenance for offshore wind and tidal developers.

Quantifiable outcome

• Successful execution of complex projects including tunnel placement of 398 tonnes (François 1er lock, Le Havre)
• +2 more outcomes

Named customers14 records

Segments5 records

Ideal customer profiles4 records

Technology focussed No

API detail

Has API

No

API docs

API detail

Core technology

AI maturity

App detail

Feature5 records

Partnerships

One partnership is on record.

• ETPO Groupe CIFEcoreStrategic or Co-development PartnerTetis is a subsidiary of ETPO Groupe CIFE. This association allows combining competencies and collaborating on large-scale maritime and fluvial construction projects. Tetis has access to ETPO's heavy equipment including large barges, cranes up to 500 tonnes, pile driving and vibro-driving equipment.

Scale indicators2 records

Recent moves6 records

Expansion highlights5 records

Broad incumbents

• Bureau Veritas: Global French-headquartered testing, inspection and certification (TIC) body. Comparable because it both certifies Tetis's diving team and competes for the in-water survey/inspection mandates that form a meaningful slice of Tetis's revenue.
• Subsea 7: Global subsea construction and inspection incumbent serving offshore energy. Overlaps with Tetis on ROV-based inspection, subsea construction and survey work, but at far larger scale and focused on offshore oil & gas and offshore wind.
• Veolia Eau: French-headquartered water infrastructure operator that is both a Tetis customer and a competitor-adjacent player. Comparable on confined-space water infrastructure works (treatment plants, pipelines, ATEX zones).
• Socotec: Major French TIC and engineering services firm with structural inspection capabilities that overlap with Tetis's non-destructive testing and underwater inspection offerings, particularly for industrial and port clients.

Direct peers

• Comex: French specialist in underwater engineering, ROV operations, hyperbaric interventions and deep-sea work. Directly comparable technology stack (diving, ROV, hyperbaric) with overlap in industrial and offshore clients.
• ETPO Groupe: Parent company of Tetis and a major French maritime/fluvial construction group. Directly comparable because it executes the same categories of work — port construction, heavy marine lifting, pile driving and underwater engineering — but at larger scale and with its own directly-employed crews.
• Stemat: French maritime and fluvial construction firm with comparable offerings in port infrastructure, dredging, and underwater works for French Atlantic and Channel ports. Direct competitor on the same tender lists served by Tetis.
• Eiffage Génie Civil Marine: Marine arm of one of France's largest construction groups, executing port, offshore and underwater works including heavy foundations. Competes with Tetis on major French maritime projects and brings larger balance-sheet scale.

Regional players

• Spie Batignolles: Major French general contractor that uses Tetis as a subcontractor and could also be considered an adjacent peer in marine and fluvial infrastructure. Comparable because it coordinates large public-tender projects where Tetis supplies the underwater specialist scope.

Emerging players

• Hydroquest: French marine renewable energy developer focused on tidal and hydrokinetic turbines. Comparable because it pulls from the same French marine renewable supply chain Tetis serves (cable burial, foundation installation, subsea maintenance).

Market position

Strengths4 records

Weaknesses4 records

Competitive moat6 records

Key risks6 records

Key highlights7 records

Customer concentration

• YouTubeyoutube.com/channel/UCbWRYLNdJLHfRWypV7YHEoA
• LinkedInlinkedin.com/company/tetis-construction

Compliance7 records

Revenue estimate

Valuation estimate

Number of profiles

Funding overview

Funding rounds

Investors

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

M&A

Investments

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

Frequently asked questions about Tetis