Drones are usually associated with unmanned flying vehicles, but autonomous watercraft also are becoming useful tools for jobs ranging from scientific exploration to law enforcement to searching for a missing airliner in the Indian Ocean.
Non-military flying drones for civilian use often rely on sunlight to recharge their batteries. But sea-faring drones, such as Wave Glider, can extract energy from the sun and the water.
Together with solar cells on their decks, these vessels use an array of specially designed underwater fins to harvest energy from the incessant up and down motion of waves on the ocean's surface.
The Wave Glider, built by California-based company Liquid Robotics, can remain at sea for months, sending data about the weather and the water to the control center via satellite.
Liquid Robotics’ president, Bill Vass, said it also can cooperate with other drones to share data. “So if you need more processing power, they'll call their friends over. And so the future is having large numbers of them working together, being able to solve some really tough problems for mankind.”
Last year, the Wave Glider broke the Guinness World Record for the longest journey by an unmanned surface vehicle when it travelled non-stop from the U.S. Pacific coast to Australia.
Another robotic ocean vessel called Saildrone is powered by the wind. It uses a freely rotating wing controlled by a special tail to travel long distances. The way it is built and designed allows it to stay upright even in the worst weather conditions.
After testing Saildrone on a journey from San Francisco to Hawaii, its builders now plan new tasks, said Saildrone’s Chief Executive Officer, Richard Jenkins.
“Phase two is equipping it with very high-grade science sensors and getting some really precise scientific data,” said Jenkins.
Jenkins sees a future for Saildrone in patrolling sea borders and enforcing laws that regulate fishing and protect endangered species.