Tethys Robotics

Tethys Robotics AG is a Swiss company based in Zurich that builds automated underwater inspection systems for rough waters. Its core product is the Tethys ONE, a compact underwater drone that delivers high-resolution inspection. The company says the system lets inspections be carried out reliably, safely and efficiently, with less exposure for professional divers. Its work is aimed mainly at offshore oil and gas and offshore wind.

Tethys ONE and offshore inspection

The compact drone is presented as a way to carry out subsea inspection anywhere and at any time. The company states that it aims to reduce danger for professional divers and to lower the environmental impact of inspection work for its customers.

• Compact drone: high-resolution inspection carried out by a small underwater vehicle.
• Offshore oil and gas: subsea inspection for oil and gas operations.
• Offshore wind: inspection work for offshore wind assets, a sector featured on its site.

Partners and deployments

The site reports that Aramco Europe showcased a Tethys ONE demonstration on a Swiss lake. In 2025 the company announced a strategic partnership with SeaRenergy Offshore Holding GmbH, an offshore service provider active in subsea operations across Europe. It also named SepcoTech as a new partner in Denmark to expand its European presence.

Expansion and partners

SeaRenergy Offshore Holding is described as an offshore service provider with a strong presence in offshore wind and a record of demanding marine projects. Tethys says the partnership brings operational insight and reach to subsea inspection services. The SepcoTech partnership in Denmark is presented as a further step in expanding its European presence.

Key facts

• Based in: Zurich, Switzerland
• Products: Tethys ONE underwater inspection drone
• Markets: offshore oil and gas and offshore wind, with European expansion