Channel between Ellesmere Island , Canada, and northwestern Greenland .
About 30–45 mi (48–72 km) wide, the sound extends northward for 55 mi (88 km) from Baffin Bay to the Kane Basin. It was discovered by William Baffin in 1616 and named for Thomas Smythe (Smith), who had promoted a number of voyages searching for a Northwest Passage .