DAIVIN! Wants to Replace Every Oxygen Tank on Earth with Water

The Macro: Oxygen Tanks Are Heavy, Dangerous, and Limiting

Scuba divers carry tanks that weigh 30 to 50 pounds and provide 45 to 90 minutes of air. Firefighters haul self-contained breathing apparatus that limits their time in a burning building. Astronauts depend on oxygen systems that represent a significant fraction of mission payload weight. In all of these cases, compressed gas cylinders are heavy, bulky, finite, and potentially explosive.

The concept of extracting breathable oxygen from water is not science fiction. Fish do it through gills. Industrial electrolysis separates water into hydrogen and oxygen routinely. The challenge has always been doing it at a scale and efficiency that works for human breathing in a portable device.

If you could build a device that extracts oxygen from water at a rate sufficient for human respiration, you would fundamentally change diving (unlimited bottom time), firefighting (no air supply constraint), space exploration (water is easier to transport than compressed oxygen), and emergency response (no running out of air in confined spaces).

DAIVIN!, backed by Y Combinator, is building exactly this: tankless breathing systems starting with diving and extending to other environments where oxygen tanks are the limiting factor.

The Micro: A Finnish Electrical Engineer Chasing Breath Autonomy

Leo Kankkunen is the founder and CEO. He is a Finnish electrical engineer with seven years of industry experience, was the youngest person in Finland to achieve the highest national electrical certification, and is a certified diver with military service background. Two-time founder with engineering credentials and the domain expertise from actually using breathing equipment underwater.

The company describes its mission as “breath autonomy,” and the technology centers on extracting breathable air from water. While the specific technical approach is not fully disclosed on the public website, the fuel cell and electrolysis patents in this space typically use polymer electrolyte membranes to electrolyze water, producing oxygen at the cathode.

The engineering challenges are significant. Human breathing requires about 6 liters of air per minute at rest and much more during exertion. Extracting that volume of oxygen from water in real time requires substantial energy, efficient membrane technology, and reliable systems that work in harsh environments.

The addressable markets, if the technology works, are massive. The global diving equipment market alone exceeds $5 billion. The firefighting equipment market is larger. Military and space applications add billions more. And the consumer appeal of tankless diving with unlimited bottom time would be transformative for the recreational diving industry.

Competitors include traditional compressed gas equipment manufacturers like Aqua Lung and Draeger, plus a few research projects exploring artificial gill technology. The space is wide open because nobody has cracked the engineering challenge at a practical scale.

The Verdict

DAIVIN! is a classic hard tech bet: if the technology works, the implications are enormous. If the physics and engineering challenges prove too steep, the product stays in the lab.

At 30 days: has the system demonstrated sustained oxygen extraction at rates sufficient for human breathing in controlled conditions?

At 60 days: what is the power consumption, and is it compatible with a portable, wearable form factor?

At 90 days: has any prototype been tested in actual underwater conditions with a human user?

I think the ambition is compelling and the applications are genuinely transformative. The fundamental question is whether current materials science and energy density can support the required oxygen extraction rates in a portable device. If DAIVIN! cracks this, it is one of the most consequential hardware startups in years. If not, it is a research project. The founder’s engineering background gives me cautious optimism.