Wellseedamm 1-3, 24145 Kiel, Germany

SubCtech GmbH


SubCtech, Kiel, offers underwater power solutions and ocean monitoring systems. We provide solutions in close collaboration with our clients – in science and in industry such as offshore oil+gas.

Li-Ion batteries, pCO2 analyzers and system solutions are our core products and a one-stop service. Our reliable and precise high-tech “Made in Germany” products are easy to handle and efficient to our customers.

Historical overview


The managing director Dipl.-Phys. Stefan Marx founded SubCtech as a management buy-out in January 2010. The team has got more than 30 years of experience. They realized solutions quickly having had previous experience in ocean engineering, the shipbuilding industry and research centres. The combination of experienced employees, young scientists and market knowledge is that successful that the company has been taking profits from the first year on.

We became a professional company having a global focus, when we got certificated as “proved vendor” in the offshore industry according to ISO 13628-6 and moved into our new premises in 2013.

The targeted implementation of corporate objectives and the cooperation 2010-2015 with the French partner for equipping sailing yachts with measurement systems were honoured with the remarkable German-French Business-Award 2013.

SubCtech is certified by ISO 9001:2015 and manufacturing according to ISO 13628-6 / API17f for design and operation of subsea production systems. Our qualified engineers are educated and certified for highest-quality IPC-A-600/610 class 3 production.

Current Profile


The realization of unresolved and challenging tasks, and the identification and utilization of new markets characterize our company. Customers are partners and are supported by our trained professional team from the first project idea onwards.

The company has a broad spectrum having the two business units of „Power solutions“ and „Ocean monitoring“.

These days the company employs 70+ staff members and is still privately owned. We count on series production with reliable selected partner companies instead of outsourcing. We solve specific customer demands flexibly due to our own R&D. Newest technologies are pursued in constant dialogue with trade associations and research institutions.

International and global scope


We reach all targeted markets with the product family of subsea Li-Ion batteries in the division „Subsea Power“. In particular, the Oil + Gas Offshore industry requires increasingly autonomous systems for greater and greater depths. Complete systems are projected together with data loggers and the implementation of sensors.

A constant level of high-quality is ensured thanks to certification and periodic audits by the Oil + Gas Industry.

Projects in depths of up to 6000m are realized in the division of „Ocean Monitoring“ with the adaptation of sensors for pCO2. The pCO2 analyzers are used for maritime surveillance and research on buoys and ships. The exclusive production of LI-COR® Biosciences pCO2 analyzers enables us to offer internationally competitive „state-of-the-art“ solutions.

Flexible solutions and a distinctive „cross innovation“ – approach clearly show the way to solve new problems and explore new markets. With the pCO2 specially equipped measuring systems of the „Ocean Pack“ family, for instance, we were able to access the mariculture and aquaculture. The water quality can be controlled better with precise and stable long-term instruments. The fish grow faster and a higher rate of yield increases the sales efficiently.

Customers are serviced on-site with the establishment of an international distribution network. Issues are resolved locally in a common language. We are engaged with our clients in a fair and cooperative business relationship that allows us to perform projects successfully. An early consultation and close cooperation during the phase of implementation avoid unpleasant surprises, as problems get identified early and can be solved together.

The targeted development of special solutions of the pCO2 analyzers and Li-ion batteries opened up the Asian market and  for instance won China as the most important export country.

Future prospects


Our social commitment keeps developing. The support of our employees and their families, like offering flexible working hours, remains a central point. Only well trained, satisfied and highly motivated employees ensure the consistency of SubCtech. We offer exchange opportunities to schools and other education establishments. International exchange programs such as AISEC or the conference YouMaRes, are supported by SubCtech and permit companies and participants to broaden their horizon.

SubCtech’s aim is the market leadership in the business divisions of Li-Ion batteries and pCO2 analyzers. We can serve customers and market demands specifically, due to the development of demanded products. SubCtech listens to its partner and develops products more efficiently.

Particular attention is paid to market niches that are of no interest to larger companies and cannot be fulfilled by small companies at the same time. For example, small data loggers are installed under ice, combined with Li-Ion batteries for high-resolution measurements, lasting in the Arctic for one year. Such niches turn out to become the new growths markets of the future.

The trend is towards automation. For example, ROV or AUV is used for subsystems such as smart and high capacitive Li-Ion batteries or sensor packs for condition monitoring.

We carefully control product development, marketing and therefore the growth of the company. Equipped with healthy equity, know-how of the employees and a network of industry, science and associations, SubCtech provides security for its employees, customers and investors.