Tethys Robotics :: Compact, Highly Automated Underwater Drones for Inspection & Assessment in Challenging Marine Environments

Tethys Robotics is a Swiss deep-tech startup and ETH Zurich spin-off specializing in compact, highly automated underwater drones for inspection and assessment in challenging marine environments. Founded to reduce risks to professional divers and improve efficiency in harsh underwater conditions, the company develops hybrid AUV/ROV systems capable of operating reliably in rough waters, confined spaces, and offshore settings. The company is based in Zurich and has raised significant funding, including a €3.5 million pre-seed round in 2025.

Tethys Robotics focuses on industries such as offshore wind, oil & gas, maritime infrastructure, and underwater maintenance. Their solutions enable faster, safer, and more cost-effective inspections while supporting sustainability goals by reducing diver operations and vessel time.

Key robot-based product:

• Tethys One: The company’s flagship compact underwater drone. It is a hybrid autonomous underwater vehicle (AUV) / remotely operated vehicle (ROV) designed for high-resolution visual inspections down to 300 meters depth. Key features include omnidirectional control for superior maneuverability, advanced autonomy, modular payloads (high-resolution cameras, sensors, lights), and robust performance in turbulent waters. It supports fully autonomous missions as well as real-time operator control when needed. The system is notably compact, making it easier to deploy from smaller vessels or shore-based operations compared to traditional large ROVs.

The Tethys One has been successfully tested in real-world scenarios, including demonstrations with Aramco and partnerships for offshore wind inspections. It is particularly effective for inspecting subsea structures, foundations, cables, and marine assets where traditional methods are dangerous, expensive, or time-consuming.

Tethys Robotics emphasizes modularity, innovation in control systems, and practical deployment. The company continues to expand its European presence through strategic partnerships (e.g., in Denmark and with SeaRenergy).