UNH Ocean Seminar

Robotic Anchoring and High Flow Rate Upwelling

Peter Lynn
Mechanical Engineer


Friday, Jan. 27, 2023, 1:30pm
Chase 105

In conjunction with Umaro Foods and the University of New Hampshire and under the ARPA-E Mariner program which seeks seaweed farming at terrestrial farming scales nominally for the production of biofuels, Otherlab has been developing an underwater robotic system for installing helical anchors and a high flow rate upwelling device. The anchoring robot is configured similarly to a quadcopter and uses thrusters for both accurate positioning and the application of torque to the helical anchor. It spins to rotate the helical anchor into the seabed, effectively performing as a large high-speed underwater electric drill/screwdriver. Helical anchors can carry loads more than a hundred times their weight, have a minimal seabed footprint, and have an installation torque to pull out strength relationship that provides high confidence in load capacity. The anchoring robot can weigh even less than the anchor it is installing and it can operate somewhat independently of weather and at depth. The helical anchoring robot provides a pathway to much faster and lower cost autonomous anchoring in a wide range of substrates and for a wide range of anchor sizes, including those needed for offshore aquaculture and offshore wind turbines.

The upwelling device is similar to an inverted ceiling fan and consists of a large diameter rotor that is suspended by a tether beneath a float. The upwelling jet can extend upward as much as ten times the rotor diameter and the bridled rotor can structurally scale to wind turbine diameters if needed. Truly large flow rates of cold nutrient rich water can be brought to the surface. The rotor rotation can be directly powered via wave pumping, with individual blades flapping up and down with the vertical movement of the surface buoy. Ocean current utilization is additionally possible and tip thrusters allow for the direct use of solar and wind energy to help drive the upwelling, they also enable cyclic control and active station keeping. Large scale upwelling can greatly increase aquaculture yield and help with ecosystem recovery, including protecting coral reefs and boosting fish stocks, enabling much higher rates of sustainable fishing. The upwelling device also has low-cost carbon removal and geoengineering possibilities.


Peter Lynn is a mechanical engineer working for Otherlab in San Francisco on early stage research and development, mostly in the energy and robotics realms. He is originally from New Zealand and was once a kiteboarding pioneer and kite designer, through which he developed an affinity for the ocean. He has delved into wind energy, solar energy, thermodynamic systems, inflatable robotics, and drones. Peter has a broad exploratory theoretical background with a strong practical bias towards prototyping and testing.