Company lists · Data refreshed September 2026

Top 25 Offshore environmental consulting worldwide

RevenueBase identified 14,755 offshore environmental consulting worldwide as of September 2026 and tracks 217,095 professional contacts across them, including 59,270 with verified work emails. The United States is the largest market and Sao Paulo the largest hub.

This list covers offshore environmental consulting worldwide, matched on what each company actually does as described in its own words. Ranked by team size, largest first. Every row shows the company's own description, its RevenueBase Smart Search rating, and when it was last checked. Data refreshed September 20, 2026. Country and city lists for offshore environmental consulting follow the table.

Published by RevenueBase, a B2B data infrastructure company. This list was built with RevenueBase Smart Search, the natural-language company search RevenueBase customers use to build their own targeted lists and unlock verified emails and direct dials at the companies on them. How these lists are built and judged.

How to read this list HQ checked on every row RevenueBase Smart Search rating on every row Refreshed Sep 20, 2026 86% judged on-target in blind review
14,755Companies
217,095Contacts tracked
59,270Verified emails
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The 25 largest offshore environmental consulting worldwide

Ranked by team size
Top 25 of 14,755 offshore environmental consulting worldwide, ranked by team size, largest first. Data refreshed Sep 20, 2026. RevenueBase Smart Search rates how each company's information relates to offshore environmental consulting: strong evidence (its own description names it), partial (names part of it), indirect (matched on the rest of its profile rather than the description shown). Click a contact count to view that company's people.
#CompanyRevenueBase Smart SearchHeadquartersEmployeesContacts
1Partial evidenceUnited StatesHQ checked Sep 20, 202610001+4,522 contacts →

Partial evidence

“A Premier Global Player with Deep Engineering Expertise in the offshore, marine and energy industries Engineering our Future Together.”

Source: RevenueBase Database · checked Sep 20, 2026
2Strong evidenceBeveren-kruibeke-zwijndrecht, BelgiumHQ checked Sep 20, 20265,001-10,0004,395 contacts →

Strong evidence

“DEME (Euronext Brussels: DEME) is a leading contractor in the fields of offshore energy, dredging and marine infrastructure, and environmental remediation.”

Source: RevenueBase Database · checked Sep 20, 2026
3Partial evidenceLeiden, NetherlandsHQ checked Sep 20, 20261,001-5,0002,643 contacts →

Partial evidence

“Heerema Marine Contractors is a world-leading marine contractor in the international offshore energy industry.”

Source: RevenueBase Database · checked Sep 20, 2026
4Partial evidenceChâtel-saint-denis, SwitzerlandHQ checked Sep 20, 20261,001-5,0002,554 contacts →

Partial evidence

“Allseas is a world-leading contractor in the offshore energy market.”

Source: RevenueBase Database · checked Sep 20, 2026
5Partial evidenceAl-khobar, Saudi ArabiaHQ checked Sep 20, 20261,001-5,0002,312 contacts →

Partial evidence

“Zamil Offshore Services Company has been offering diversified offshore and marine support services to the oil and gas industry since 1977.”

Source: RevenueBase Database · checked Sep 20, 2026
6Partial evidenceAbu Dhabi, United Arab EmiratesHQ checked Sep 20, 20261,001-5,0001,917 contacts →

Partial evidence

“ZMI Holdings an ADNOC L&S company THE NEW WAVE Transforming the Offshore Energy Industry An integrated service provider offering unparalleled commitment.”

Source: RevenueBase Database · checked Sep 20, 2026
7Strong evidencePhoenix, AZ, United StatesHQ checked Sep 20, 20261,001-5,0001,629 contacts →

Strong evidence

“Founded on a commitment to sound science and creative solutions, SWCA is a leader in environmental and management consulting services.”

Source: RevenueBase Database · checked Sep 20, 2026
8Partial evidenceLittle Rock, AR, United StatesHQ checked Sep 20, 20261,001-5,0001,529 contacts →

Partial evidence

“Onterris (formerly Montrose Environmental Group) was one of the first to see environmental responsibility as not just an imperative but as a strategic asset.”

Source: RevenueBase Database · checked Sep 20, 2026
9Partial evidenceÇankaya, TürkiyeHQ checked Sep 20, 2026501-1,0001,501 contacts →

Partial evidence

“TP-OTC is established to provide all engineering and technology services for offshore operations in oil and gas industry.”

Source: RevenueBase Database · checked Sep 20, 2026
10Indirect evidenceRio De Janeiro, BrazilHQ checked Sep 20, 2026201-5001,407 contacts →

Indirect evidence

“With more than 50 years of legacy, Maersk Supply Service celebrates a new important milestone: from November 1st, our headquarters are officially located in Brazil.”

Source: RevenueBase Database · checked Sep 20, 2026
11Indirect evidenceOslo, NorwayHQ checked Sep 20, 20261,001-5,0001,375 contacts →

Indirect evidence

“DeepOcean is a technology-driven, independent solution provider in the ocean space.”

Source: RevenueBase Database · checked Sep 20, 2026
12Indirect evidenceAbu Dhabi, United Arab EmiratesHQ checked Sep 20, 2026201-5001,279 contacts →

Indirect evidence

“(Underwater Engineering) S.A.L was established in 1976.”

Source: RevenueBase Database · checked Sep 20, 2026
13Indirect evidenceUnited Arab EmiratesHQ checked Sep 20, 20261,001-5,0001,216 contacts →

Indirect evidence

“Aries is the largest Engineering, Inspection & Maintenance firm in the Middle East.”

Source: RevenueBase Database · checked Sep 20, 2026
14Indirect evidenceHøjbjerg, DenmarkHQ checked Sep 20, 2026n/a1,176 contacts →

Indirect evidence

“Miljø er vores kernekompetence og vores ansvar.”

Source: RevenueBase Database · checked Sep 20, 2026
15Indirect evidenceRockville, MD, United StatesHQ checked Sep 20, 20261,001-5,0001,137 contacts →

Indirect evidence

“Who is Apex?”

Source: RevenueBase Database · checked Sep 20, 2026
16Strong evidenceMinneapolis, MN, United StatesHQ checked Sep 20, 20261,001-5,0001,088 contacts →

Strong evidence

“Barr provides engineering and environmental consulting services to clients across the Midwest, throughout the Americas, and around the world.”

Source: RevenueBase Database · checked Sep 20, 2026
17Indirect evidenceLaksevåg, NorwayHQ checked Sep 20, 20261,001-5,0001,031 contacts →

Indirect evidence

“Shearwater is a global marine geoscience and technology business.”

Source: RevenueBase Database · checked Sep 20, 2026
18Partial evidenceDallas, TX, United StatesHQ checked Sep 20, 20261,001-5,000961 contacts →

Partial evidence

“Trinity Consultants is a global team of experts helping organizations solve complex challenges in environmental compliance, ecological protection, infrastructure performance, and…”

Source: RevenueBase Database · checked Sep 20, 2026
19Partial evidenceKhobar, Saudi ArabiaHQ checked Sep 20, 2026501-1,000916 contacts →

Partial evidence

“Provides first-class marine offshore Services to the Oil & Gas sector in the Arabian Gulf region and beyond.”

Source: RevenueBase Database · checked Sep 20, 2026
20Partial evidenceKochi, IndiaHQ checked Sep 20, 20261,001-5,000900 contacts →

Partial evidence

“Mantle Solutions is the registered offshore technology and professional services firm for LuLu Group International, a highly diversified conglomerate with business entities…”

Source: RevenueBase Database · checked Sep 20, 2026
21Indirect evidenceLafayette, LA, United StatesHQ checked Sep 20, 20261,001-5,000865 contacts →

Indirect evidence

“ATC Group Services LLC is now Atlas.”

Source: RevenueBase Database · checked Sep 20, 2026
22Strong evidenceSantiago, ChileHQ checked Sep 20, 2026501-1,000807 contacts →

Strong evidence

“We are Pares & Alvarez, our extensive experience and the recognition of our clients makes us one of the leading Engineering Companies in environmental, consulting, engineering and…”

Source: RevenueBase Database · checked Sep 20, 2026
23Indirect evidenceLondon, United KingdomHQ checked Sep 20, 20261,001-5,000804 contacts →

Indirect evidence

“The Energy and Marine Consultants - an Aqualis company.”

Source: RevenueBase Database · checked Sep 20, 2026
24Indirect evidenceOslo, NorwayHQ checked Sep 20, 2026501-1,000768 contacts →

Indirect evidence

“AGR – an Aqualis company – is a multidisciplinary consultancy, specialising in drilling & wells, subsurface, marine and subsea solutions, resourcing, technical safety and software…”

Source: RevenueBase Database · checked Sep 20, 2026
25Partial evidenceSão Paulo, BrazilHQ checked Sep 20, 20261,001-5,000767 contacts →

Partial evidence

“Somos uma empresa de engenharia industrial especializada em serviços Onshore e Offshore, braço operacional do Grupo Azevedo & Travassos.”

Source: RevenueBase Database · checked Sep 20, 2026

Showing 25 of 14,755 offshore environmental consulting worldwide

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Offshore environmental consulting worldwide at a glance

As of Sep 20, 2026
27.3%Verified-email coverage
14.7Average contacts per company
1-10Median size (employees)
1.2%Largest-city concentration · Sao Paulo
Sep 20, 2026Page data refreshed

Companies by employee count

1-10
8,915
11-50
4,237
51-200
1,111
201-500
261
501-1,000
82
1,001-5,000
71
5,001-10,000
10
10001+
10

Email recency is reported on each country list linked below.

How this list was built

Company categories are rarely black and white. RevenueBase reads each company's own description of its business to decide whether it belongs among offshore environmental consulting, so some rows will be adjacent to the category rather than pure plays. The description and RevenueBase Smart Search rating on every row are there so you can check each match yourself.

Source
The RevenueBase company graph: 60 million companies and 398.9 million professional contacts resolved from primary sources, queried with RevenueBase Smart Search, the natural-language company search available to every RevenueBase user.
Coverage
Every country. Country and city lists for offshore environmental consulting are linked below.
What qualifies
Companies worldwide whose own description of what they do matches “offshore environmental consulting”. Matching reads each company's description, not its industry code or its name.
RevenueBase Smart Search
RevenueBase Smart Search is how this list is assembled and how each row is rated. RevenueBase's data engine and AI assess a company's LinkedIn profile, information supplied directly by the company, its website and other publicly available information, then relate it to a category defined in a user's own words. Each row is rated strong evidence (its own description names offshore environmental consulting), partial evidence (it names part of the category) or indirect evidence (the description shown names none of it and the match rests on the rest of the company's profile). The description supporting each rating is quoted on the row.
What we exclude
Companies whose own description does not clearly place them among offshore environmental consulting, and records with no verified work email.
Match quality
In blind human judging of this matching method, 86% of matched companies were on target. Expect roughly 1 in 7 rows to be adjacent to the category rather than a pure play. Every row shows the company's own description and its RevenueBase Smart Search rating so you can judge each match yourself. Read the full methodology: how the lists are built, how the judging worked, and what the figure means.
Ranking
Team size, largest first: companies are ordered by the number of professionals RevenueBase tracks at each one. Employee ranges shown are reported bands, for context.
Verification
Every listed company carries at least one verified work email, 59,270 across the full list. Contacts re-verify on a rolling cadence, and each contact's own verification date is shown inside RevenueBase.
Refresh
This page's figures were pulled from the company graph on September 20, 2026. Lists refresh periodically as the graph is re-checked.
Corrections
Wrong category, wrong headquarters, or a company that has closed? Use “Report an issue” on any row. Reports go to the RevenueBase Data Team and feed back into the company graph.

Offshore environmental consulting by location

61 lists · largest first

Every Offshore environmental consulting list RevenueBase publishes, by country and city. Counts are matching companies in each list as of its own refresh date.

Countries

Cities

Frequently asked

What is RevenueBase Smart Search?

RevenueBase Smart Search is how RevenueBase decides which companies belong on this list and how strongly each one fits. Its data engine and AI assess a company's LinkedIn profile, information supplied directly by the company, its website and other publicly available information, then relate it to the category the list is about. Each row is rated strong evidence when the company's own description names offshore environmental consulting, partial evidence when it names part of the category, and indirect evidence when the description shown names none of it and the match rests on the rest of the company's profile.

How many offshore environmental consulting are there worldwide?

RevenueBase identified 14,755 offshore environmental consulting worldwide as of September 2026, matched on each company's own description of what it does rather than its industry code.

What is the largest company on this list?

Seatrium, headquartered in Worldwide, tops this list with the largest team on record.

Which country has the most offshore environmental consulting?

The United States leads with 2,352 companies, followed by Brazil (2,037) and the United Kingdom (1,005). Every offshore environmental consulting list by country and city is linked on this page.

Which city has the most offshore environmental consulting?

Sao Paulo leads with 184 headquartered companies, followed by Rio De Janeiro (155) and Houston (148).

How do I get contact information for these companies?

A free RevenueBase account lets you run this exact search and work the top results, verified emails and direct dials included. Upgrading unlocks all 59,270 verified decision-maker contacts tracked across these 14,755 companies.

How current is this list?

The list refreshes periodically as the company graph is re-checked. This page's figures were pulled on September 20, 2026.

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About this data

RevenueBase is a B2B data infrastructure company. Its company graph covers 60 million companies and 398.9 million professional contacts, with emails verified on a rolling cadence rather than scraped once and left to decay. These company lists are generated directly from that graph with RevenueBase Smart Search, the same natural-language company search every RevenueBase user has: describe a market in plain words, get the companies that match, and add verified emails and direct dials for the people at them. It is the same data that powers RevenueBase's B2B data products, and a free account includes 500 credits to start. How these lists are built and judged.