For years, pilots have observed strong and unusual currents in the 2.4-kilometer-long (1.5-mile-long), 300-meter-wide (984-foot-wide) canal connecting Lake Varna with the Black Sea. Maarja Kruusmaa, an academician and professor at Tallinn University of Technology, and researcher Laura Piho, working with the Port of Varna, undertook detailed measurements to determine the causes of the phenomenon.