Message in a Bottle Launched in Drake Passage Reaches Tasmania After Two Years

A glass bottle containing a message, deployed in the Drake Passage in February 2023, reached Tasmania’s western coast in August 2025, according to an announcement from the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (AWI).

The container was released by German marine geologist Johann Klages, affiliated with AWI, north of the 60° south latitude marker as his expedition aboard the research vessel Polarstern concluded. The discovery was made by Toby Ray, an employee of the Australian Central Coast Council, during an excursion to the remote western shoreline of Tasmania. Klages was informed of the finding via email on December 9, 2025, after an initial letter sent by Ray was returned as undeliverable.

The recovery holds scientific interest due to the bottle’s estimated trajectory, believed to have followed the Antarctic Circumpolar Current (ACC) clockwise around Antarctica. The journey covered more than 15,000 kilometers, completed in a maximum span of 900 days. The ACC, also known as the West Wind Drift, is the planet's largest current system, with an estimated mean transport of 137 ± 7 Sverdrups (Sv), or approximately 137 million cubic meters per second, equivalent to the combined flow of all the world's rivers.

The Drake Passage is a critical constriction point for the ACC as it moves from the Pacific to the Atlantic Ocean, where the narrowing effect accelerates the current’s velocity near the Antarctic Convergence zone at 60° S latitude. Researchers plan to construct a detailed model to map the bottle’s precise path, offering a tangible data point for validating oceanographic models concerning surface drift patterns in the Southern Ocean. The vessel used for the launch, the RV Polarstern, is a German research icebreaker commissioned in 1982, capable of operating in temperatures as low as -50 °C and breaking through 1.5-meter-thick ice.

This successful drift underscores the persistent nature of the currents governing the Southern Ocean’s circulation. The event provides a case study in ocean dynamics, particularly as climate models suggest the ACC’s strength may decline by up to 20% by 2050 due to polar ocean freshening.