Company lists · Data refreshed September 2026

Top 25 Underwater construction firms based in Norway

Name: Underwater construction firms based in Norway
Creator: RevenueBase
License: https://creativecommons.org/licenses/by/4.0/

Compiled by the RevenueBase Data Team Data refreshed Sep 19, 2026 101 companies tracked

RevenueBase identified 101 underwater construction firms headquartered in Norway as of September 2026 and tracks 3,648 professional contacts across them, including 976 with verified work emails. Haugesund is the largest hub.

This list covers underwater construction firms headquartered in Norway, 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 19, 2026.

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 19, 2026 86% judged on-target in blind review

101Companies

3,648Contacts tracked

976Verified emails

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The 25 largest underwater construction firms based in Norway

Ranked by team size

Top 25 of 101 underwater construction firms based in Norway, ranked by team size, largest first. Data refreshed Sep 19, 2026. RevenueBase Smart Search rates how each company's information relates to underwater construction firms: 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.
#	Company	RevenueBase Smart Search	Headquarters	Employees	Contacts
1	Island Offshore	Indirect evidence	Ulsteinvik, NorwayHQ checked Sep 19, 2026	501-1,000	501 contacts →
	Indirect evidence “Island Offshore - The Island Offshore Group is a leading provider of services to the offshore industry ranging from Platform Supply, Walk-to-work and Anchor Handling to Advanced…” Source: RevenueBase Database · checked Sep 19, 2026
2	Global Maritime	Indirect evidence	Stavanger, NorwayHQ checked Sep 19, 2026	201-500	472 contacts →
	Indirect evidence “Global Maritime delivers integrated marine solutions for a changing offshore world.” Source: RevenueBase Database · checked Sep 19, 2026
3	Reach Subsea	Indirect evidence	Haugesund, NorwayHQ checked Sep 19, 2026	201-500	454 contacts →
	Indirect evidence “Reach Subsea ASA (“Reach Subsea”, “Reach” or “the Group”) is a prominent offshore contractor that offer high quality solutions and technology to clients in need of ocean data and…” Source: RevenueBase Database · checked Sep 19, 2026
4	Ocean Installer	Partial evidence	Stavanger, NorwayHQ checked Sep 19, 2026	201-500	299 contacts →
	Partial evidence “Ocean Installer is a leading marine construction company that specializes in offshore installation services with more than 15 years of experience delivering large and complex…” Source: RevenueBase Database · checked Sep 19, 2026
5	Akofs Offshore	Partial evidence	Oslo, NorwayHQ checked Sep 19, 2026	201-500	233 contacts →
	Partial evidence “AKOFS Offshore is a global provider of vessel based subsea well construction and intervention services to the oil and gas industry.” Source: RevenueBase Database · checked Sep 19, 2026
6	Imenco	Indirect evidence	Aksdal, NorwayHQ checked Sep 19, 2026	201-500	199 contacts →
	Indirect evidence “Imenco is a group of companies working mainly in five main business areas: Offshore oil & gas, offshore renewables, aquaculture, marine & naval and industrial.” Source: RevenueBase Database · checked Sep 19, 2026
7	Havila Subsea & Renewables	Partial evidence	Aalesund, NorwayHQ checked Sep 19, 2026	201-500	120 contacts →
	Partial evidence “Havila Subsea & Renewables operates an advanced fleet of vessels dedicated to Diving, Offshore Inspection, Repair, and Maintenance (IRM), as well as Construction.” Source: RevenueBase Database · checked Sep 19, 2026
8	Abyss AS	Indirect evidence	Kristiansund, NorwayHQ checked Sep 19, 2026	201-500	84 contacts →
	Indirect evidence “Abyss utfører alle tjenester på sjøen - over og under vann.” Source: RevenueBase Database · checked Sep 19, 2026
9	Moss Maritime	Indirect evidence	Lysaker, NorwayHQ checked Sep 19, 2026	51-200	65 contacts →
	Indirect evidence “Moss Maritime provides leading technology and expertise within design and engineering services to the offshore energy sector as well as other ocean-based sectors.” Source: RevenueBase Database · checked Sep 19, 2026
10	Subseadesign AS	Indirect evidence	Lierbyen, NorwayHQ checked Sep 19, 2026	51-200	47 contacts →
	Indirect evidence “SubseaDesign (SD) is an engineering, design and fabrication company providing equipment and services for the oil and gas industry.” Source: RevenueBase Database · checked Sep 19, 2026
11	Subseapartner AS	Indirect evidence	Haugesund, NorwayHQ checked Sep 19, 2026	11-50	44 contacts →
	Indirect evidence “SubseaPartner is a leading diving contractor in the shallow-deep segment.” Source: RevenueBase Database · checked Sep 19, 2026
12	Swire Seabed	Indirect evidence	Bergen, NorwayHQ checked Sep 19, 2026	51-200	40 contacts →
	Indirect evidence “Swire Seabed provides a highly flexible range of integrated subsea services to the global Oil & Gas and renewables industries.” Source: RevenueBase Database · checked Sep 19, 2026
13	Innova	Partial evidence	Sandnes, NorwayHQ checked Sep 19, 2026	51-200	38 contacts →
	Partial evidence “Established in 1997, Innova is a leading supplier of services, equipment and solutions to the international underwater industry.” Source: RevenueBase Database · checked Sep 19, 2026
14	Kystdesign	Indirect evidence	Aksdal, NorwayHQ checked Sep 19, 2026	51-200	37 contacts →
	Indirect evidence “KYSTDESIGN delivers a wide range of products for the subsea oil- and gas industry, renewables, research and fish farming.” Source: RevenueBase Database · checked Sep 19, 2026
15	Techno Dive	Indirect evidence	Avaldsnes, NorwayHQ checked Sep 19, 2026	11-50	25 contacts →
	Indirect evidence “Techno Dive is your partner for Safe and Efficient Subsea Work.” Source: RevenueBase Database · checked Sep 19, 2026
16	Rexor Marine AS	Indirect evidence	Tananger, NorwayHQ checked Sep 19, 2026	51-200	24 contacts →
	Indirect evidence “Rexor Marine er en annerledes og spennende aktør innen arbeidsdykking, havnearbeid og bemanning i regionen.” Source: RevenueBase Database · checked Sep 19, 2026
17	Samba Marin AS	Indirect evidence	Lepsøy, NorwayHQ checked Sep 19, 2026	11-50	24 contacts →
	Indirect evidence “Vi leverer tjenester innen Havbruk, Offshore, Bygg- og Anlegg” Source: RevenueBase Database · checked Sep 19, 2026
18	Aquastructures AS	Indirect evidence	Trondheim, NorwayHQ checked Sep 19, 2026	11-50	23 contacts →
	Indirect evidence “Aquastructures is recognized and acknowledged as an innovative and leading engineering house, establishing long term client relations, finding viable and sustainable technical…” Source: RevenueBase Database · checked Sep 19, 2026
19	Noble Installation AS	Indirect evidence	Rudskogen, NorwayHQ checked Sep 19, 2026	51-200	23 contacts →
	Indirect evidence “Om NOBLE INSTALLATION AS: Heleid datterselskap av Noble AS, etablert i Vår virksomhet er innenfor marine operasjoner, offshore installasjon, mekanisk montasje og produksjon.” Source: RevenueBase Database · checked Sep 19, 2026
20	Stinger Technology AS	Partial evidence	Stavanger, NorwayHQ checked Sep 19, 2026	11-50	23 contacts →
	Partial evidence “Stinger Technology AS is an innovative solution provider focusing on underwater wells monitoring, seabed surveys and jacket inspections.” Source: RevenueBase Database · checked Sep 19, 2026
21	A S Delprodukt	Indirect evidence	Melhus, NorwayHQ checked Sep 19, 2026	51-200	23 contacts →
	Indirect evidence “Delprodukt is a leading supplier of mechanical services within land based industry, shipping and maritime, energy production, offshore and sub-sea, plate and welding services…” Source: RevenueBase Database · checked Sep 19, 2026
22	Sjøentreprenøren AS	Indirect evidence	Bergen, NorwayHQ checked Sep 19, 2026	11-50	22 contacts →
	Indirect evidence “Vi utfører oppdrag innen mudring, sprenging, riving, konstruksjon, inspeksjon og mye mer under vann.” Source: RevenueBase Database · checked Sep 19, 2026
23	Submara Prosjekt AS	Indirect evidence	Tofte, NorwayHQ checked Sep 19, 2026	11-50	21 contacts →
	Indirect evidence “Dykkerteknikk AS ble etablert i 1976 og er et godt etablert selskap innen undervannsarbeid og marine operasjoner.” Source: RevenueBase Database · checked Sep 19, 2026
24	Kvenna	Indirect evidence	Ålesund, NorwayHQ checked Sep 19, 2026	11-50	21 contacts →
	Indirect evidence “Kvenna is located in the beautiful city of Aalesund, Norway.” Source: RevenueBase Database · checked Sep 19, 2026
25	Deep C	Indirect evidence	Kristiansund, NorwayHQ checked Sep 19, 2026	11-50	21 contacts →
	Indirect evidence “Deep C provides Seabed Intervention Services that simply fit together.” Source: RevenueBase Database · checked Sep 19, 2026

RevenueBase Smart Search

RevenueBase Smart Search assesses information from a company’s LinkedIn profile, information supplied directly by the company, its website, and other publicly available sources. It uses that information to rate how closely the company relates to this list’s category: underwater construction firms. Every row carries its rating and the description the rating was read from, so each one can be checked rather than taken on trust.

Strong evidence: The company's own public description of its business names underwater construction firms.
Partial evidence: Its own public description names part of underwater construction firms, so it works in or next to the category without describing itself that way.
Indirect evidence: The description shown does not name underwater construction firms. The match rests on the rest of the company's public profile rather than the one sentence quoted here, so this is the rating to check first.

RevenueBase Smart Search is how these lists are built: RevenueBase's data engine and AI assemble the companies that match a category defined in a user's own words, so a list can be about what companies actually do rather than about whichever industry code they were filed under.

Showing 25 of 101 underwater construction firms based in Norway

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Underwater construction firms based in Norway at a glance

As of Sep 19, 2026

26.8%Verified-email coverage

36.1Average contacts per company

11-50Median size (employees)

8.9%Largest-city concentration · Haugesund

Sep 19, 2026Page data refreshed

Companies by employee count

1-10

11-50

51-200

201-500

501-1,000

10001+

Email recency for this list is measured worldwide rather than for Norway, so it is reported there. Company counts and contact totals on this page are exact for Norway, over 101 companies.

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 underwater construction firms, 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.
What qualifies: Companies headquartered in Norway whose own description of what they do matches “underwater construction firms”. 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 underwater construction firms), 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 underwater construction firms, and records with no verified work email. Companies headquartered outside Norway are excluded even when they keep an office there.
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, 976 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 19, 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.

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 underwater construction firms, 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 underwater construction firms are there based in Norway?

RevenueBase identified 101 underwater construction firms headquartered in Norway 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?

Island Offshore, headquartered in Ulsteinvik, tops this list with the largest team on record.

Which city has the most underwater construction firms?

Haugesund leads with 9 headquartered companies, followed by Oslo (8) and Stavanger (4).

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 976 verified decision-maker contacts tracked across these 101 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 19, 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.