Tethys Robotics
About
About Tethys Robotics
Tethys Robotics builds the Tethys ONE underwater inspection drone for work in rivers, tidal currents and subsea infrastructure. The 35-kilogram vehicle is rated to 300 metres depth, offers a 400-metre extendable wired range and runs for up to four hours on hot-swappable batteries. It can hold position in currents up to 3.5 knots.
Tethys ONE combines repeatable area coverage and structure scanning with omnidirectional movement, DVL navigation, forward- and side-looking sonar, terrain following and obstacle awareness. Operators can add manipulators, multibeam sonar, metal detection, cathodic-protection and thickness probes, while the interface supports live mission recording, points of interest and post-processed photogrammetric or bathymetric 3D models.
Products
Supply
Supply chain relationships
- Nortek
Inbound - Positioning & Navigation - Tethys Robotics uses Nortek DVL 500 Compact to support navigation and localization on its compact underwater inspection robot
Source - Reach Robotics
Inbound - actuation and motion control - Tethys Robotics integrated a Reach Alpha grabber for military EOD, search and rescue use cases
Source
Funding
- 2025-10-30 - Pre-seed - $4.1M - Tethys Robotics raises EUR 3.5M pre-seed round
Tethys Robotics raised EUR 3.5 million in pre-seed funding for autonomous underwater inspection systems. - source: venturelab.swiss
Investors
- Alpine VC - Participant - Angel / Individual - 1 funding event - first seen 2025-10-30
- ETH Foundation - Participant - Angel / Individual - 1 funding event - first seen 2025-10-30
- Euregio+ - Participant - Unknown - 1 funding event - first seen 2025-10-30
- Kickfund - Participant - VC - 1 funding event - first seen 2025-10-30
- Redstone - Lead - Unknown - 1 funding event - first seen 2025-10-30
- Venture Kick - Participant - VC - 1 funding event - first seen 2025-10-30
- Zurcher Kantonalbank - Participant - Angel / Individual - 1 funding event - first seen 2025-10-30
Timeline
Events
- 2025-10-30 - Funding - Tethys Robotics raises EUR 3.5M pre-seed round
Redstone led the round, with Euregio+, Alpine VC, Zürcher Kantonalbank, ETH Foundation, Kickfund and Venture Kick participating. The capital supported engineering, data teams, production scale-up and commercial operations across Europe. The capital supports robot sensing, actuation, compute or communications systems as Tethys Robotics moves toward broader commercial use.
Source - 2025-10-16 - Demonstration - Aramco Europe completes Tethys ONE lake demonstration
Aramco Europe described the Swiss-lake demonstration as completed. The Tethys-supplied unit was evaluated for automated inspection of complex underwater infrastructure. A real-facility test in Saudi Arabia was a next step, not yet a completed deployment.
Source - 2025-07-29 - Partnership - Tethys names SepcoTech as Denmark partner for subsea systems
SepcoTech was named as Tethys' new partner in Denmark. The collaboration targets defence and offshore inspection applications. The announcement describes market representation, not a completed customer sale or deployment.
Source - 2025-05-27 - Partnership - Tethys partners with SeaRenergy for offshore subsea inspection
The partnership targets offshore inspection work in the North Sea and Baltic Sea regions. SeaRenergy is the named offshore services partner.
Source - 2024-08-22 - Product Launch - Tethys Robotics releases new Tethys ONE underwater drone
The 35-kilogram system combines pilot-controlled ROV operation with autonomous AUV operation. Tethys specified operation to 300 metres and position holding in currents up to 3.5 knots. The modular payload architecture supports cameras, acoustic sensors, metal detection, UT, XRF and manipulators.
Source - 2021-05-18 - Partnership - Tethys Robotics integrates Reach Alpha grabber
Reach Alpha supplied the grabber integrated with Tethys Robotics’ underwater platform. The configuration supports military explosive-ordnance disposal,search-and-rescue and related subsea missions. The manipulator gives the vehicle a physical intervention tool rather than limiting it to observation-only work.
Source
Relations
Relationships
- SeaRenergy
Technology Partner - Tethys Robotics partnered with SeaRenergy for offshore subsea inspection services.