Subctech

What Subctech does

SubCtech GmbH is a Kiel, Germany-based designer and manufacturer of underwater power systems and autonomous ocean monitoring instruments, founded around 2009 and acquired by Gabler Maschinenbau GmbH (Possehl Group) in August 2025. The company operates two product lines: Ocean Power, comprising rechargeable Li-Ion battery packs (PowerPacks, Long-John, Big-Jim, Big-Jim XL) with titanium pressure housings rated to 6000m depth, SmartChargers, subsea batteries, AUV/ROV vehicle batteries, and a new 1–6 MWh Energy Storage System; and Ocean Monitoring, comprising the OceanPack family of autonomous underway measurement systems (RACK, CUBE, RACE, AQUA, BUOY) plus the NetDI controller, OceanView software, PowerLogger, subsea landers and frames, microplastic and plankton samplers, nutrient analyzers, and the OceanXpert pCO2/greenhouse-gas analyzer. All products are certified to API17F, MIL-STD, UN T38.3, and DNV-GL for offshore oil & gas and maritime use, and the pCO2 analyzers are SOCAT-compliant for climate research.

The business sells exclusively through direct sales and quote-based engagement to enterprise and scientific customers worldwide, with no public pricing. End markets are marine research institutes (GEOMAR, AWI, Fraunhofer, Max Planck), offshore energy operators and service companies (Equinor, Chevron, Allseas, Schlumberger, OneSubsea, Sonardyne), AUV/ROV manufacturers (Cellula Robotics), and high-profile ocean racing teams (Malizia-Seaexplorer, Team Holcim-PRB, Ocean Race fleets). The go-to-market is heavily augmented by participation in industry trade shows (Oceanology International, OTC Houston, ONS), scientific conferences, sailing sponsorships, and YouTube content. Revenue is not publicly disclosed. Following the August 2025 acquisition, SubCtech operates within the Gabler Ocean group alongside Develogic GmbH and north.io GmbH, with founder Stefan Marx continuing as Managing Director.

Name

Subctech

Legal name

SubCtech GmbH

Website

https://subctech.com

Company type

Private

Founded year

2009

Operating status

Operating

Short description

SubCtech GmbH is a Kiel, Germany-based manufacturer of subsea Li-Ion battery systems and autonomous OceanPack FerryBox monitoring instruments, serving offshore energy, marine research, AUV/ROV, and ocean racing customers globally. Acquired by Gabler Maschinenbau (Possehl Group) in August 2025.

Ownership category

akta.pro rank

Product category

Subsea Batteries & Ocean Monitoring Equipment

NAICS

Ship Building and Repairing (336611), Search, Detection, Navigation, Guidance, Aeronautical, and Nautical System and Instrument Manufacturing (334511), Ship and Boat Building (33661)

SIC

Oil & Gas Field Machinery & Equipment (3533), Industrial Instruments For Measurement, Display, And Control (3823), Ship & Boat Building & Repairing (3730)

akta.pro primary industry

Marine Power Generation & Energy Storage (Generators, Batteries, UPS) (IMAJAJAB)

akta.pro secondary industries

Marine Sensors, Instrumentation & IoT (Condition Monitoring) (IMAJAJAI), Energy Storage Systems for Marine (Batteries, supercapacitors) (IMAJAHAJ)

Keywords

• Subsea battery systems
• Ocean monitoring equipment
• Ferrybox measurement systems
• Underwater lithium batteries
• Marine environmental sensors

Headquarters

HQ city

Kiel

HQ country

Germany

HQ region

Europe

Offices3 records

Markets served

GTM type

B2B

Offering type

Hardware or Manufacturing

Cost components

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

Revenue model

1. Ocean Power Products: Sale of Li-Ion batteries including subsea batteries, vehicle batteries (AUV/ROV), basic batteries, energy storage systems, custom batteries, and smart chargers. Products are certified according to API17F, MIL-STD, UN T38.3, DNV-GL standards
2. Ocean Monitoring Products: Sale of autonomous underway measurement systems (OceanPack RACK, CUBE, RACE, AQUA), subsea monitoring systems, sensors, samplers, and monitoring components including pCO2 analyzers
3. Customized Solutions: Bespoke battery and monitoring system development for specific customer requirements, engineering services
4. Consulting Services: Technical consulting for maritime technology applications and system integration

Go-to-market motion1 record

Distribution channels2 records

Marketing channels6 records

Core offering

SubCtech GmbH designs, manufactures and sells two integrated product lines for the marine and subsea markets: (1) Ocean Power — rechargeable Li-Ion battery packs, subsea batteries, vehicle batteries for AUVs/ROVs, scalable Energy Storage Systems (1–6 MWh), smart chargers and customised batteries, all with titanium pressure housings rated to 6000 m depth and certified to API17F, MIL-STD, UN T38.3 and DNV-GL; and (2) Ocean Monitoring — autonomous underway FerryBox measurement systems (OceanPack RACK, CUBE, RACE, AQUA, BUOY) plus sensors, samplers, subsea frames, landers and the NetDI controller for measuring pCO2, salinity, temperature, dissolved oxygen, pH, turbidity, nutrients and microplastics.

Product overview

SubCtech operates two main business units: Ocean Power and Ocean Monitoring. Ocean Power includes rechargeable Li-ion batteries branded as PowerPacks (Long-John, Big-Jim, Big-Jim XL series), SmartChargers, Subsea Batteries, Vehicle Batteries, Energy Storage Systems (ESS scalable 1-6 MWh), and Customized Batteries—all featuring titanium pressure housings for depths up to 6000m with certifications including API17F, MIL-STD, UN T38.3, DNV-GL. Ocean Monitoring comprises the OceanPack family of autonomous underway measurement systems (FerryBox): RACK (19-inch rack for larger vessels), CUBE (compact robust format), RACE (waterproof compact for racing yachts), and BUOY (subsea buoy), complemented by subsea frames and landers, PowerLogger and Subsea NetDI data loggers, Top-Box and NetDI Deck-Units, OceanView Software, Nutrient Analyzers, OceanXpert CO2 Analyzers, and autonomous samplers (Plankton Sampler, Microplastic Sampler). All systems are controlled via the NetDI controller with serial interfaces and support various sensors for pCO2, salinity, temperature, dissolved oxygen, pH, turbidity, and nutrients. The company was acquired by Gabler Maschinenbau (Possehl Group) in August 2025.

Differentiator

Problem solved

Functional benefit

Brands

• OceanPack: Family of autonomous underway measurement systems (FerryBox) for ocean monitoring including parameters such as pCO2, temperature, salinity, dissolved oxygen, and turbidity. Includes OceanPack RACK, CUBE, RACE, and AQUA variants.
• PowerPack
• SmartCharger
• PowerLogger
• NetDI
• OceanXpert
• gosubsea 3000

Products and services

• OceanPack RACK 19-inch rack-mounted autonomous underway measurement system (FerryBox) for environmental monitoring on larger vessels, with modular design and high-precision wet-chemical nutrient analysis capability.
• OceanPack CUBE
• OceanPack RACE Compact waterproof autonomous underway measuring system designed for racing yachts and high-speed vessels, featuring climate data acquisition at the ocean-atmosphere interface.
• OceanPack AQUA
• OceanPack BUOY
• NetDI Controller
• PowerLogger
• Subsea NetDI Logger
• Subsea Frames
• Lander
• OceanXpert CO2 Analyzer
• Nutrient Analyzers
• Plankton Sampler
• Microplastic Sampler Autonomous underway microplastic sampling system that catches smallest ocean surface microplastic particles through size fractioning (300-100-30 μm filters), operable standalone or with OceanPack systems, at high boat speeds and rough sea without crew requirement.
• PowerPacks (Li-ion Batteries) — Long-John, Big-Jim, Big-Jim XL series
• Subsea Batteries
• Vehicle Batteries (Li-Ion PowerPack format)
• Energy Storage System (ESS) High-performance, highly reliable and high-safety Li-Ion Energy Storage System for offshore subsea applications, scalable from 1 MWh to 6 MWh, with stainless steel tube housings for deep-sea conditions.
• SmartCharger
• Customised Batteries

Quantifiable outcome

• Battery systems operating at depths up to 6000m with titanium corrosion-free housings
• +2 more outcomes

Named customers12 records

Segments4 records

Ideal customer profiles4 records

Technology focussed Yes

API detail

Has API

No

API docs

API detail

Core technology

AI maturity

App detail

Integration9 records

AI capability2 records

Feature7 records

Partnerships

Three partnerships are on record, tiered core and minor.

• Gabler Maschinenbau GmbH / Possehl GroupcoreStrategic or Co-development Partner · 11 August 2025Gabler Maschinenbau GmbH, member of the Possehl Group, acquired SubCtech. SubCtech becomes part of Gabler Ocean group alongside Develogic GmbH and north.io GmbH. Stefan Marx continues as managing director. The acquisition combines SubCtech's underwater energy and ocean monitoring technology with Gabler's maritime machinery expertise.
• Mocean EnergycoreStrategic or Co-development Partner · 3 September 2024SubCtech and Mocean Energy signed a Memorandum of Understanding to develop customisable ocean power and monitoring solutions powered by wave, sun and battery technologies for subsea applications. The partnership combines Mocean's Blue X wave energy converter with SubCtech's battery and monitoring systems to deliver standalone low carbon subsea solutions globally.
• Maritime Cluster Northern GermanyminorOthersLong-term partnership as member of the Maritime Cluster Northern Germany (MCND), supporting regional maritime technology ecosystem

Scale indicators5 records

Recent moves6 records

Expansion highlights6 records

Direct peers

• Saft (TotalEnergies): Saft is a leading manufacturer of advanced Li-ion batteries for marine, subsea, and offshore energy applications, including subsea-resident power systems—directly comparable to SubCtech's PowerPacks and Energy Storage Systems.
• Sea-Bird Scientific: Sea-Bird Scientific designs and manufactures oceanographic sensors and CTDs used in FerryBox-class underway monitoring—a direct competitor to SubCtech's OceanPack measurement systems for temperature, salinity, and dissolved oxygen.
• Aanderaa Data Instruments (Xylem): Aanderaa, part of Xylem, produces marine sensors and oceanographic instrumentation widely deployed on research vessels—directly comparable to SubCtech's OceanPack RACK/CUBE sensor suites.
• AML Oceanographic: AML Oceanographic manufactures CTDs and oceanographic sensors used for underway and profiling measurements, overlapping with SubCtech's NetDI-controlled sensor integrations.
• nke Instrumentation: nke Instrumentation produces oceanographic sensors and in-situ measurement platforms used in marine research and FerryBox applications—closely aligned with SubCtech's OceanPack family and NetDI ecosystem.
• Corvus Energy: Corvus Energy specializes in Li-ion energy storage systems for marine and offshore vessels, directly comparable to SubCtech's 1–6 MWh subsea Energy Storage System line.

Broad incumbents

• Teledyne Marine: Teledyne Marine is a large portfolio of marine instruments, batteries, sonars, and AUV systems; overlaps with SubCtech across oceanographic instrumentation, AUV power, and subsea monitoring, but at significantly greater scale and breadth.
• Kongsberg Maritime: Kongsberg Maritime is a global marine-technology incumbent offering AUVs, subsea sensors, and ocean instrumentation; competes with SubCtech in subsea monitoring and offshore battery systems but as part of a much broader portfolio.
• Kongsberg Discovery: Kongsberg Discovery offers subsea sensor systems and AUV platforms used in marine research and offshore energy—adjacent to SubCtech's subsea monitoring and battery business.

Others

• Develogic GmbH: Subsea instrumentation specialist now part of Gabler Ocean alongside SubCtech; develops subsea sensor and data systems that complement SubCtech's monitoring portfolio within the same parent group.

Market position

Strengths5 records

Weaknesses5 records

Competitive moat5 records

Key risks6 records

Key highlights7 records

Customer concentration

• YouTubeyoutube.com/watch?v=Clxrl5Gufek
• LinkedInlinkedin.com/company/3257191

Compliance5 records

Revenue estimate

Valuation estimate

Number of profiles

Profiles2 records

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 Subctech