Teledyne Marine has announced that Silbo, its Slocum G2 Glider, recently completed a four-plus year journey that circumnavigated the Atlantic Ocean in four legs, which is considered a first for an AUV.

Manufactured by Teledyne Webb Research, Silbo was named in honor of its 2011 maiden voyage from Teledyne Gavia in Iceland to the Canary Islands, which is a Spanish archipelago off the coast of northwestern Africa. Silbo then went on to complete a western crossing of the Atlantic Ocean.

In preparation to circle the Atlantic Ocean, Silbo was updated in 2016 at the Teledyne factory with an extended energy bay and thruster.

In early spring 2016, Silbo was launched from Cape Cod, Massachusetts. After launching, the AUV interacted with international science teams from several countries and collected scientific and critical engineering data along the way for a variety of programs before returning to Cape Cod in late June 2020. Besides a scratched hull repair, the only maintenance that Silbo received during its three stops was an external cleaning and a fresh set of batteries.

“Born out of Dr. Rick Spinrad's challenge to build a robot that can cross the Atlantic, these long-endurance oceanic scale basin crossings with little yellow submarines are becoming more and more routine,” says Clayton Jones, senior director of Technology Teledyne Webb Research.

“Along the way, we continue to entrain international and educational outreach and better our global ocean predictive skills – a testament to the foresight of Dr. Henry Stommel and Douglas Webb who were instrumental in bringing undersea gliders to life.”

During the first leg from Cape Cod to Ireland, Silbo covered a distance of 6,557 kilometers in 330 days. While in Ireland, Silbo participated in a Glider Training session hosted by the Marine Institute and P&O Maritime Services, Galway.

During the second leg, Silbo flew from Ireland to revisit the Canary Islands, covering 3,695 kilometers in 178 days. The AUV participated in “glider school” at the research facility Oceanic Platform of the Canary Islands (PLOCAN) and the University of Las Palmas de Gran Canaria (ULPCG).

The third leg took 418 days, which is believed to be another autonomous glider record. During this leg, Silbo flew from the Canary Islands to St. Thomas, U.S. Virgin Islands, again crossing the Atlantic Ocean and gliding 6,256 kilometers. Teledyne technicians recovered, re-batteried and re-deployed Silbo in less than 24 hours with support from staff and students from University of the Virgin Islands (UVI), St. Thomas.

Silbo's fourth and final journey from St. Thomas began on July 18, 2019 and concluded south of Martha's Vineyard on June 29 of this year. The final 6,236-kilometer trek was completed in 348 days. During this transit, Silbo spent three months flying a butterfly pattern south of Bermuda, as it contributed data to Bermuda Atlantic Time-series Study (BATS). Silbo then joined the Gulf Stream and became the season's first storm glider as Tropical Storm Arthur passed directly over the glider.

In total, Silbo covered 22,744 kilometers and spent roughly 1,273 days at sea.

During its four-year journey, Silbo collected hurricane data, corrected current models, and provided close to 5,000 CTD casts that aided metalogical forecasting.

Silbo also participated in the Challenger glider mission with partners from Rutgers University and its student base, UVI, PLOCAN, UGCLP, the Marine Institute, and others.

According to Teledyne, Silbo has been a test bed for many new engineering hardware and software features for existing Slocum gliders, as well as next generation Slocum gliders. Recent legs have provided data on new battery configurations, advanced software, and techniques for piloting long endurance missions and minimizing biofouling.

Teledyne adds that Silbo's accomplishments “have been critical in the glider community's understanding of techniques used to increase robot durations at sea.”