MIKUNIYA

What MIKUNIYA does

MIKUNIYA (三国屋建設株式会社) is a Japanese marine construction and salvage specialist founded in 1972 and headquartered in Kamisu, Ibaraki Prefecture. The company provides five core service lines—salvage operations, marine civil engineering, survey and measurement, underwater inspection and hull cleaning, and special construction—to government agencies (port authorities, fishing port associations, coastal infrastructure bodies) and private marine/industrial clients across the Kanto region and wider Japan. Its service offering covers the full underwater/marine construction lifecycle from bathymetric and geophysical survey through to construction, maintenance, and emergency response including oil spill remediation.

The company operates one of Japan's largest specialized marine fleets, with over 400 vessels including crane-equipped barges, self-propelled crane vessels (most notably the newly commissioned 700-ton DPS vessel "Ibaraki 700"), work boats, dive boats, backhoe barges, and modular assembly barges (SD series). Its proprietary technology portfolio includes dismantlable crane barges that pass through low bridges and reassemble on-site, telescopic spud barges for overhead-restricted areas, dynamic positioning system (DPS) vessels for anchor-free operations, and a deep-water rock dumping system (ROCKBERM) capable of accurate rock placement in waters exceeding 100 meters. Survey and inspection capabilities are supported by ROV underwater drones, narrow multibeam sonar, GNSS positioning systems, UAV aerial drones, and certified commercial divers.

MIKUNIYA generates revenue through project-based contracts for marine construction, salvage, survey, and emergency-response services, with pricing quoted per project depending on scope, equipment, and site conditions. Distribution is direct-to-client with no intermediary channels, supported by a Tokyo regional office, four regional equipment centers (Kashima, Ichihara, Tokai, Kansai), and a Funabashi Port disaster-prevention base. The company also operates a wholly-owned consulting subsidiary focused on environmental and social infrastructure technical services. MIKUNIYA is a private, founder-led corporation under Representative Director Wada Eiji (和田英司), with no institutional investment, PE/VC funding, or public market listing disclosed.

Name

MIKUNIYA

Legal name

三国屋建設株式会社

Website

https://mikuniya-web.jp

Company type

Private

Founded year

1972

Operating status

Operating

Headcount range

101–250 employees

Short description

MIKUNIYA (三国屋建設株式会社) is a Japan-based marine construction and salvage specialist serving government agencies, port authorities, and private marine/industrial clients with a 400+ vessel fleet, including crane barges, DPS vessels, ROVs, and sonar survey systems.

Ownership category

akta.pro rank

Product category

Marine Construction & Salvage Services

NAICS

Ship Building and Repairing (336611), Support Activities for Water Transportation (4883)

SIC

Ship & Boat Building & Repairing (3730)

akta.pro primary industry

Underwater Inspection, Maintenance & Repair (UWILD, Diving/ROV, In-water Cleaning) (IMAJAFAJ)

akta.pro secondary industries

Underwater Hull Services (Diving, In-Water Cleaning, Propeller Polishing, Inspection) (TLAHAMAL), Emergency Towage & Rescue (Refloating, Grounding Response) (IMAJANAB), Heavy Lift & Marine Recovery (Cranes, Lift Barges, Rigging) (IMAJANAC), Heavy Lifting & Material Handling Infrastructure (Goliath Cranes, Jib Cranes, Hoists) (IMAJALAD)

Keywords

• Marine civil engineering
• Salvage operations
• Underwater construction
• Port infrastructure construction
• Marine survey services

Headquarters

HQ city

Kamisu

HQ country

Japan

HQ region

Asia

Offices7 records

Markets served

GTM type

B2B

Offering type

Services

Cost components

Infrastructure, Personnel, Supply Chain, Operations, Technology or R&D

Revenue model

1. Marine Construction Services: Provides specialized marine civil engineering, salvage, underwater survey/mapping, and special construction services to government agencies, port authorities, and private companies. Revenue generated through project-based contracts for construction, maintenance, and emergency response services.

Go-to-market motion1 record

Distribution channels1 record

Marketing channels4 records

Core offering

MIKUNIYA is a specialized marine contractor that performs salvage operations, marine civil engineering, survey and measurement, underwater inspection/hull cleaning, and special construction for port, harbor, fishing port, and coastal infrastructure. Services are delivered using a self-owned fleet of 400+ specialized vessels (including crane barges, DPS vessels, work boats, dive boats, and modular SD-series barges) supported by ROVs, narrow multibeam sonar, GNSS, and UAV surveying systems.

Product overview

MIKUNIYA (三国屋建設株式会社) is a specialized marine construction and salvage company offering comprehensive services in five core areas: salvage operations, marine civil engineering, survey and measurement, underwater inspection/hull cleaning, and special construction. The company operates one of Japan's largest fleets of marine vessels including self-propelled crane vessels (up to 700-ton capacity), over 100 work barges, assembly barge systems (SD series), and ROV underwater drones. Their technology portfolio includes narrow multibeam sonar for 3D seabed mapping, GNSS survey systems, UAV drones, and advanced DPS (Dynamic Positioning System) vessels capable of operations in waters exceeding 100m depth. They also maintain an emergency oil spill response base with substantial equipment reserves.

Differentiator

Problem solved

Functional benefit

Products and services

• Salvage Operations (サルベージ事業) Professional salvage of vessels, structures, and cargo in marine environments.
• Marine Civil Engineering (海洋土木業務) Construction and maintenance of port facilities, harbors, fishing ports, and coastal structures.
• Survey and Measurement Services (調査・測量業務) Bathymetric surveys, coastline mapping, underwater structure inspection, and geophysical surveys using sonar and GNSS equipment.
• Underwater Inspection and Hull Cleaning (水中検査・ハルクリーニング事業) Underwater visual inspection, corrosion assessment, and hull cleaning services for vessels and marine structures.
• Special Construction (特殊工事事業) Specialized marine construction services including underwater welding, cutting, and installation of marine structures.
• DPS Full-Slewing Crane Vessel 'Ibaraki 700' (いばらき７００) New 700-ton lifting capacity DPS full-slewing crane vessel used as the company's flagship asset for marine construction and salvage operations.
• Oil Spill Response Equipment & Materials (油防除機器・資材) Complete oil spill response inventory including diaphragm pumps, hot-water high-pressure washers, oil skimmers, oil fences, oil absorbent mats, and dispersant sprayers for environmental emergencies.
• Funabashi Disaster Prevention Base (船橋防災基地) Funabashi Port emergency response facility maintaining stockpiled oil spill response materials including oil fences, absorbent mats, and skimming equipment for oil pollution emergencies.

Quantifiable outcome

• Zero serious workplace accidents - company safety target and achievement

Segments2 records

Ideal customer profiles2 records

Technology focussed Yes

API detail

Has API

No

API docs

API detail

Core technology

AI maturity

App detail

Feature4 records

Partnerships

Two partnerships are on record, tiered core.

• 三国屋建設コンサルタント株式会社coreOthersGroup company providing environmental and social infrastructure technical services including field surveys, problem identification, and solutions for natural environment and social infrastructure preservation.
• 株)関海事工業所coreTechnology or IntegrationTechnical partnership for DPS vessels (Dynamic Positioning System) and deep water rock dumping systems (ROV Treminy System). Joint technology for operations in waters exceeding 100m depth.

Scale indicators5 records

Recent moves8 records

Expansion highlights5 records

Direct peers

• Fukada Salvage Co., Ltd. Japanese marine salvage and offshore contractor with similar underwater construction capabilities. Regional competitor in Japan's marine services market.
• Wakachiku Construction Co., Ltd. Japanese marine construction specialist focused on ports, harbors, and coastal infrastructure. Direct competitor for government port construction contracts.
• Nippon Salvage Co., Ltd. Japan's largest marine salvage specialist with similar emergency response and refloating capabilities. Most direct competitor in salvage and underwater services where MIKUNIYA operates.
• Kido Construction Co., Ltd. Japanese underwater and marine civil engineering contractor. Comparable in scale and service mix, particularly for underwater foundations and port construction.

Broad incumbents

• IHI Corporation: Major Japanese industrial conglomerate with significant marine equipment manufacturing and infrastructure divisions. Operates broadly in marine engineering including underwater foundations.
• Penta-Ocean Construction: Large Japanese marine and civil engineering contractor with significant offshore and port construction operations. National-scale competitor in marine civil engineering.
• Toa Corporation: Major Japanese marine civil engineering contractor with comprehensive port, harbor, and offshore construction capabilities. Larger scale than MIKUNIYA with similar marine construction focus.

Market position

Strengths5 records

Weaknesses5 records

Competitive moat4 records

Key risks6 records

Key highlights7 records

Customer concentration

• Instagraminstagram.com/mikuniya_construction

Revenue estimate

Valuation estimate

Number of profiles

Profiles5 records

Subsidiaries1 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 MIKUNIYA