Answer: A Saildrone.
The National Oceanic and Atmospheric Administration (NOAA) recently employed one to sail all the way around Antarctica, which it did successfully despite colliding with an iceberg.
Developed by a company of the same name, the Saildrone is 23 feet long, unmanned, and powered by wind and solar energy. The bright orange vessel can be equipped with sensors to take scientific measurements. The recent trip around Antarctica served a dual purpose, providing NOAA with data on how much carbon dioxide the ocean is absorbing from the air and testing the Saildrone’s ability to handle the rough seas.
Other than a significant collision with a large iceberg (the exact size of the berg is unknown because the incident occurred at night), the drone fared well and passed its test. Some of its instruments for weather monitoring were damaged in the crash, but it was still able to successfully complete its mission.