After five years and 8,700 mi (14,000 km), a lost oceanographic instrument package has turned up on a beach in Tasmania. The deep-ocean monitoring equipment belonging to Britain's National Oceanography Centre (NOC) was lost on Christmas Day 2013 in the northern Drake Passage after a failed recovery effort, but was found by a Tasmanian resident after an epic drift clear across the South Pacific.

The ocean is a very big and often very dangerous place, and to properly study it scientists have for centuries relied on floating experiments to gather information. Sometimes these are as simple as bottles containing a note and a request for whoever found it to let the scientists know where it was picked up, and others are elaborate buoys stuffed with sophisticated instruments and a satellite telemetry uplink.

Unfortunately, the sea being what it is, not all of these survive and many are lost in the search for knowledge. Such was the case with the NOC deep-sea lander that was dropped in 2009 into the narrows between the tip of South America and Antarctica to a depth of 1,100 m (3,600 ft). Its purpose was to measure sea-bottom pressures to gain a better understanding of the globe-encircling Antarctic Circumpolar Current, but when it came time for the British Antarctic Survey's Royal Research Ship (RRS) James Clark Ross to recover it, it did not return to the surface.

The conclusion at the time was that the release mechanism had become tangled and that it was trapped on the bottom, but it turns out that it somehow came adrift and floated to Tasmania, where it was identified by its serial numbers on two of the sensors.

According to NOC, several trips and the help of the Australian scientific research agency, the CSIRO, and the Integrated Marine Observing System (IMOS) at the University of Tasmania resulted in the recovery of the instruments, frame and data sensors. The hope is that the recovered data will help scientist piece together the undersea trek of the device.

"Finding this instrument is like an early Christmas present," says Professor Ed Hill, Executive Director of the NOC. "The Antarctic Circumpolar Current is key to understanding the dynamics of the global ocean, so these sustained observations are incredibly important. There is no better place to make these observations than the narrow Drake Passage, which is why this instrument was deployed there before it made its epic journey to Tasmania."

Source: NOC