CIOMAR

What CIOMAR does

CIOMAR S.L. (Construcciones y Obras Marítimas) is a Spanish specialty maritime and underwater construction contractor founded in 1990 by Antonio González Antón and headquartered in Isla, Arnuero, Cantabria. The company provides a comprehensive suite of underwater and port-infrastructure services, including dredging, underwater concrete pouring, marine formwork, diamond wire cutting, underwater welding, caisson recovery, bathymetric studies, subsea inspections, and breakwater/quay construction. Its principal physical asset is the Cantabria Seis split-hopper dredger — 47.88m in length with a 600m³ hopper, 80-ton crane, and TOYO DP-20 pump delivering 1,000-1,500m³ daily yield — supported by hyperbaric chambers, underwater communication systems, and precision GNSS/GPS positioning with decimetric-to-centimetric accuracy.

CIOMAR generates revenue almost entirely through competitive public-works tenders (licitación de obras públicas) and subcontracts with tier-1 construction primes (Dragados, Ferrovial, FCC, SACYR). Contract values range from approximately €530K for smaller repair works to €32.1M for the Portmán Bay environmental regeneration joint venture. The company holds direct official classification from Spain's Junta Consultiva de Contratación Administrativa covering dredging (F-1), breakwaters (F-2), concrete blocks (F-3), piles (F-5), and general maritime works (F-7), and is certified under ISO 9001:2015, ISO 14001:2015, and ISO 45001:2018. Operating geographies span all Spanish coastal autonomous communities plus Latin America (Puerto Quetzal, Guatemala) and Gibraltar.

The business model is project-based and non-recurring: revenue depends on winning tenders rather than subscription or retainer contracts, and customer mix is dominated by government port authorities (Autoridad Portuaria de Bilbao), national ministries (Ministerio de Agricultura, Alimentación y Medio Ambiente), regional governments (Gobierno Vasco, Gobierno de Cantabria), and municipal authorities (Ayuntamiento de Estepona). With approximately 50+ personnel across four operating teams and limited external capital, CIOMAR functions as a focused, founder-led specialty contractor rather than a scaled platform business.

Name

CIOMAR

Legal name

CIOMAR S.L.

Website

https://ciomar.es

Company type

Private

Founded year

1990

Operating status

Operating

Headcount range

1–10 employees

Short description

CIOMAR is a Spanish specialty maritime and underwater construction contractor serving government port authorities, ministries, and tier-1 construction primes across all Spanish coastal regions plus Latin America. It delivers dredging, port infrastructure, and subsea engineering via competitive public tenders, anchored by its Cantabria Seis split-hopper dredger.

Ownership category

akta.pro rank

Product category

Maritime and Underwater Construction Services

NAICS

Port and Harbor Operations (488310), Support Activities for Water Transportation (4883), Ship Building and Repairing (336611)

SIC

Ship & Boat Building & Repairing (3730)

akta.pro primary industry

Navigation & Aids-to-Navigation Works (Beacons, Buoys, Markers) (IMAFAJAH)

akta.pro secondary industries

Underwater Inspection, Maintenance & Repair (UWILD, Diving/ROV, In-water Cleaning) (IMAJAFAJ), Underwater/Port Infrastructure Security (Dive Teams, Hull & Pier Inspections) (BPAKALAH), Underwater Cutting, Demolition & Obstruction Removal (TLAHAIAI)

Keywords

• Maritime construction services
• Underwater construction works
• Port dredging services
• Breakwater construction
• Commercial diving services

Headquarters

HQ city

Isla (Arnuero)

HQ country

Spain

HQ region

Europe

Offices1 record

Markets served

GTM type

B2B

Offering type

Services

Cost components

Personnel, Operations, Infrastructure, Supply Chain, Marketing or Sales

Revenue model

1. Maritime Construction Contracts: CIOMAR generates revenue through competitive bidding on public and private maritime construction contracts. Projects include dredging, pier construction, underwater repairs, breakwater construction, and port regeneration. Revenue is project-based with contracts ranging from smaller repair works (530,700€) to major infrastructure projects (32.1 million € Portmán Bay regeneration). The company qualifies directly for public works tenders.

Pricing tiers

Go-to-market motion1 record

Distribution channels3 records

Marketing channels2 records

Core offering

CIOMAR provides specialized maritime and underwater construction services for ports, harbors, and coastal infrastructure across Spain and selected international markets. Its work includes dredging, marine formwork, underwater concrete placement, diamond wire cutting, underwater welding, dock and breakwater construction, caisson recovery, bathymetric surveys, and subsea inspections. Projects are won through competitive public works tenders or as subcontracted specialty scopes to prime construction firms.

Product overview

CIOMAR (Construcciones y Obras Marítimas) is a maritime and underwater construction services company with over 25 years of experience. The company offers a comprehensive portfolio of specialized marine construction services centered around underwater works, dredging, and port infrastructure. The primary product is the Cantabria Seis split-hopper dredger vessel, complemented by a range of service offerings including marine formwork, diamond wire cutting, underwater concrete, prefabricated underwater elements, bathymetric studies, diving services, and dock construction. The company operates primarily in Spain (all coastal autonomous communities) and has expanded internationally to Latin America (Guatemala).

Differentiator

Problem solved

Functional benefit

Quantifiable outcome

• Able to work at depths of 20 meters with limited daily dive time (110 minutes/day requiring 2 hours decompression)
• +1 more outcomes

Named customers12 records

Segments4 records

Ideal customer profiles3 records

Technology focussed No

API detail

Has API

No

API docs

API detail

Core technology

AI maturity

App detail

Feature3 records

Partnerships

Two partnerships are on record, tiered minor and core.

• COPISA Constructora Guatemala Sociedad AnónimaminorStrategic or Co-development Partner · 21 December 2015CIOMAR contracted by COPISA to perform underwater slope conditioning, geotextil panel placement and concrete filling under the docks of Puerto Quetzal container terminal in Guatemala. COPISA is the main contractor executing the port construction works.
• SomhidroscoreStrategic or Co-development Partner · 19 August 2015UTE (temporary joint venture) formed between Ciomar and Somhidros for design and installation of the tallest geyser in Spain at Estepona. Somhidros specializes in ornamental fountain design. The project budget was 1.5 million euros with the geyser reaching 100 meters height. Companies are also exploring opportunities in United Arab Emirates for similar ornamental installations.

Scale indicators5 records

Recent moves6 records

Expansion highlights5 records

Broad incumbents

• DEME Group: Belgian marine engineering and dredging specialist with operations across offshore, marine infrastructure, and environmental remediation. Comparable to CIOMAR through port construction, dredging, and specialized underwater work, particularly the environmental regeneration angle similar to Portmán Bay.
• Jan De Nul Group: Belgian family-owned marine contractor with leading global dredging and offshore capabilities. Comparable to CIOMAR through specialized underwater construction and marine infrastructure work, though Jan De Nul operates globally at much larger scale with its own vessel fleet.
• Dragados: Spanish construction company (part of ACS Group) with major marine and port infrastructure capabilities. Comparable to CIOMAR as both client and competitor - Dragados bids on the same large port projects (e.g., Marina Vela Barcelona) and subcontracts specialized underwater work to firms like CIOMAR.
• Ferrovial: Spanish infrastructure multinational with significant marine construction and port project portfolio. Comparable to CIOMAR as both a major client and competitor on Spanish port tenders, often partnering with or subcontracting specialty underwater firms for the underwater components.
• FCC Construcción: Major Spanish construction company (part of FCC Group) with port and marine infrastructure capabilities. Comparable to CIOMAR as both a subcontracting client (UTE FCC-Ascan partnership at Puerto de Laredo) and competitor on major Spanish port tenders.
• Van Oord: Dutch marine contractor specializing in dredging, offshore wind, and coastal infrastructure. Comparable to CIOMAR through port construction, breakwater work, and underwater construction services, though Van Oord operates globally at significantly larger scale and broader service portfolio.
• Royal Boskalis Westminster: Dutch global leader in marine services and dredging with extensive operations in ports, harbors, and coastal infrastructure worldwide. Comparable to CIOMAR through core dredging and marine construction capabilities, though operating at vastly larger scale and broader geographic reach across global tender markets.
• SACYR: Spanish construction and infrastructure company with extensive concessions and port development operations. Comparable to CIOMAR through overlapping project portfolios in Spanish port construction, both as competitor for end contracts and as client for specialized underwater work packages.
• Acciona: Spanish infrastructure multinational with marine construction and port development operations. Comparable to CIOMAR through overlapping work in Spanish coastal and port infrastructure projects where specialized underwater capabilities are subcontracted.

Others

• Royal IHC: Dutch marine equipment and services company providing dredgers, specialized vessels, and underwater technology. Comparable to CIOMAR as an enabling peer in marine construction - Royal IHC builds the type of split hopper dredger (Cantabria Seis) that CIOMAR operates and supplies related underwater technology.

Market position

Strengths5 records

Weaknesses5 records

Competitive moat4 records

Key risks6 records

Key highlights7 records

Customer concentration

• LinkedInlinkedin.com/company/ciomar

Compliance3 records

Revenue estimate

Valuation estimate

Number of profiles

Profiles1 record

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 CIOMAR