A self-controlled swimming robot has completed a journey from San Francisco to Australia.
A second robot is scheduled to make it to Australia early next year, and though one robot has to return to Hawaii for repair, another is currently en route to Japan.
The record-breaking 9,000 nautical mile (16,668km) trip took the PacX Wave Glider just over a year to achieve.
Liquid Robotics, the US company behind the project, collected data about the Pacific Ocean's temperature, salinity and ecosystem (wave heights and frequency, weather, fluorescence and dissolved oxygen) from the drone.
Papa Mau also observed phytoplankton blooms around the equator in the Pacific, measuring increased concentrations of chlorophyll-A, confirming an increase in such events since the late 1960s caused by climate change.
Liquid Robotics chief scientist Luke Beatman told iTnews that approximately five million data points have been gathered by Papa Mau.
Different sets of data are collected from the Wave Gliders, Beatman said.
"We have the the environmental data that measures what's going around the Wave Glider, and the scientific data," Beatman said.
The second US-Australia Wave Glider, Benjamin, is continuing to transmit data.
The Wave Gliders communicate with the Internet using the Iridium satellite network, which allows for 2400 bits per second data speeds.
This allows the Wave Gliders to provide real-time data to researchers, a feature that Beatman said is unique and really surprised him when he started work at Liquid Robotics.
The company said its success demonstrated that such technology could "survive the high seas".
However, Beatman said the Wave Gliders also utilise Iridium's RUDICS (Router-Based Unrestricted Digital Internetworking Connectivity Solutions) that allows customers to send and receive data traffic over the Iridium network using an optimised circuit switched data channel.
Nevertheless, Beatman admits that using the Iridium service which has standard charges of US$1.20 ($1.15) per 1000 bytes is the big budget item in the Liquid Robotics PacX project.
Data gleaned by the Wave Riders is presented through a web interface, in comma separated values format for analysis by researchers.
The PacX voyage so far.
A short documentary on the occasion of Papa Mau's arrival in Australia
The robot is called Papa Mau in honour of the late Micronesian navigator Pius "Mau" Piailug, who had a reputation for finding ways to navigate the seas without using traditional equipment.
"During Papa Mau's journey, [it] weathered gale-force storms, fended off sharks, spent more than 365 days at sea, skirted around the Great Barrier Reef, and finally battled and surfed the east Australian current to reach his final destination in Hervey Bay, near Bundaberg, Queensland," the company said in a statement.
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Some of the data it gathered about the abundance of phytoplankton - plant-like organisms that convert carbon dioxide into oxygen and provide food for other sea life - could already be monitored by satellite.
However, the company suggested that its equipment offered more detail, providing a useful tool for climate model scientists.
Liquid Robotics still has a further three robots at sea.
A second is due to land in Australia early next year.
Another pair had been heading to Japan, but one of them has suffered damage and has been diverted to Hawaii for repair.
Each robot is composed of two halves: the upper part, shaped like a stunted surfboard, is attached by a cable to a lower part that sports a series of fins and a keel.
They do not use fuel but instead convert energy from the ocean's waves, turning it into forward thrust.
Solar panels installed on the upper surface of the gliders power numerous sensors that take readings every 10 minutes.
Mixing electronics and water might sound like a risky idea - but Dr Jeremy Wyatt, from the school of computer science at the University of Birmingham, said there was good reason there was so much interest in marine robotics.
"The ocean is a very big place and therefore a safe place to test autonomous robots - these Wave Gliders move slowly and have a low risk of bumping into other objects," he said.
"There are also autonomous sailing competitions in which craft plot their journey completely independently - unlike the Wave Gliders which autonomously follow a prescribed route - and there are a variety of types: robots which bob on the ocean surface, gliders and even fully autonomous submarines which plan their own routes and dive to collect data.
Eventually, Liquid Robotics hopes to have hundreds of next generation Wave Gliders with improved solar panels for more power traversing the oceans, and believes the solution is scalable.
Several uses are envisaged for teams of Wave Riders, including early detection of cataclysmic events such as tsunamis through pressure and wave height sensors.
"We are reaching a tipping point in that the technology is becoming so cheap that it's now a much cheaper to use a robot to gather data than to pay for a manned ship to be at sea for months at a time."
- CNET : Science robot ends Guinness record-breaking ocean journey
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- GeoGarage blog : Liquid Robotics to launch wave gliders to collect oceanographic data / Liquid Robotics to usher era of smart oceans with autonomous robots