Wave Glider: Autonomous Floating Robot Navigates Adventures on High Seas

by Samantha Zee

Swells. Ships. Sharks. And a software engineering role where snorkeling is a requirement.

These all appealed to James Gosling, known as the father of the Java programming language, when he joined Liquid Robotics five years ago to build the Wave Glider SV3 and other unmanned ocean-going robots.

Wave Glider SV3 during beta testing in Hawaii.
Wave Glider SV3 during beta testing in Hawaii.

The Wave Glider resembles a nine-foot-long lozenge that’s part surfboard and part kayak, Gosling said. It floats on the ocean’s surface using waves and solar energy to fuel its hybrid power and propulsion system, enabling the platform to gather and process data over long durations. Missions with heavy compute loads deploy the Jetson TK1.

It’s sturdy enough to navigate challenging ocean conditions, including high currents, hurricanes and the occasional encounter with curious creatures like sharks, orcas and seals.

“The No. 1 criteria for the Wave Glider is that it must survive hurricanes. So far, it’s survived 17,” Gosling told a packed room of attendees at NVIDIA’s GPU Technology Conference.

Mimicking Whales

Part of the Wave Glider’s unique two-part architecture is a winged rack submerged in the water beneath the float and attached by a fixed umbilical line. The rack helps provide forward propulsion, which helps the robot survive harsh conditions, he said.

The Wave Glider uses an auxiliary vectored thruster (which resembles a rudder and is often described as a “thrudder”) for extra speed to address difficult ocean conditions, or to quickly accommodate changes in operational needs.

A Wave Glider SV3 with its hybrid propulsion system.
A Wave Glider SV3 with its hybrid propulsion system.

The winged rack’s mechanism “almost exactly mimics what happens when a whale’s tail moves through the water,” Gosling said.

Liquid Robotics has built more 350 Wave Gliders, with at least a dozen missions underway at any given time.

The unmanned surfboard-shaped robots are used by the military and defense groups, oil and gas companies, and marine and environmental groups. Operating them successfully requires a heavy compute load — perfect for the Jetson TK1 — because out in the ocean, “you are alone,” Gosling said.

Navigating Solo

For missions requiring heavy compute loads, engineers at Liquid Robotics, based in Sunnyvale, California, and Kamuela, Hawaii, use an NVIDIA Jetson TK1 on a Liquid Robotics production board, along with a communications board. These are sealed in compartments inside the titanium and carbon fiber Wave Glider.

“There’s always a problem with salt water incursions, or some ocean critter chomping, or a short of some sort, so we have to measure and monitor every wire.

Wave Glider SV3s on their way to launch.
Wave Glider SV3s on their way to launch.

The power supply is dramatically more complex than the control system,” Gosling said.

Gosling and his team communicate with the unmanned robot using Iridium satellite connections, which are costly.

“The need for autonomy is extreme because you think about communication very differently,” he said.

Connectors cost more than disk drives because they have to survive salt water.

As the Wave Glider navigates the ocean alone, often for months at a time, the powerful Jetson can be programmed to detect and avoid collisions with ships, measure ocean temperature and pressure, monitor everything from pollution to radiation, count fish populations and detect tsunamis.

When anything goes wrong, sometimes a software engineer needs to don a wetsuit, which “makes debugging more fun than usual,” Gosling said.