Autonomous Robotic Deep Sea Lander


TURTLE II is an autonomous robotic deep sea lander, which has been developed by INESC TEC, the Autonomous Systems Laboratory (LSA) of the School of Engineering of the Polytechnic Institute of Porto (ISEP), the Portuguese Navy Research Centre (CINAV), and A. Silva Matos Metalomecânica (the latter was the leader of the consortium). It is operating since 2019.

TURTLE is a hybrid lander, being capable of staying at the bottom of the sea for long periods of time, but also of autonomously relocating itself and surfacing for maintenance operations. It is also able to dive and ascend with high-energy efficiency, and its autonomous capabilities allow for reduced operational costs and flexibility.



  • Vehicle type: autonomous robotic deep sea lander
  • Body materials: syntatic foam, stainless steel
  • Deployment: four hooks for craning, and capability to be towed
  • Length: 1.5 m
  • Width: 1.5 m
  • Height: 1.5 m
  • Weight in air: 600 kg
  • Power: rechargeable batteries (LiFePO4, 8 kWh, extensible)
  • Battery charge time: 6 h
  • Payload capacity: 30 kg
  • Payload interfaces/ports: ethernet, serial RS232/485, with underwater connectors


  • USBL
  • DVL
  • Multibeam
  • Pressure sensors
  • Altimeter
  • Video camera + lasers
  • SLS system
  • Seismometer
  • Acoustic pinger
  • Hydrophone to gather ocean sound data or launch alerts
  • Additional payload capability


  • Hybrid lander combining mobility with long-term presence in the deep sea
  • Autonomous positioning
  • Hovering capability without disturbing sea floor and water turbidity
  • Energy efficient technologies for ascent-descent operations
  • Untethered system (no cables sent to the surface)
  • Modular, light and pressure resistant mechanical structures
  • On-board processing and sensor data logging
  • Robotic technologies, enabling reduced maintenance and operational requirements
  • Increases human presence and observation capabilities in the deep sea



  • Transportation and deployment of materials and tools to the seabed
  • Communications and navigation support for underwater systems


  • Ocean observatories
  • Marine biology monitoring
  • Oceanography
  • Seismic and acoustic activity monitoring


  • Harbour protection
  • Border monitoring
  • Intruder detection and monitoring