Baffin Bay pack ice. Winds are predominantly north-western through the whole year. South-eastern and eastern winds are common in July and August. Between May and July (sometimes April), a significant portion of navigable open water (polynya) forms at the extreme north of the bay, presumably due to the relatively warm Greenland Current. With an area of about in summer, it is the largest polynya of the Canadian Arctic and covers the Smith Sound between the Ellesmere Island and Greenland. This polynya has a stable position and existed for at least 9,000 years. It was first described in 1616 by William Baffin and
Davis Strait Davis Strait is underlain by complex geological features of buried grabens (basins) and ridges, probably formed by strike-slip faulting during Paleogene times about 45 million to 62 million years ago. The strike-slip faulting transferred plate-tectonic motions in the Labrador Sea to Baffin Bay. It is the world's broadest strait. With a water depth of between one and two thousand meters the strait is substantially shallower than the Labrador Sea to the south or Baffin Bay to the north. The strait is famous for its fierce tides that can range from , which discouraged many earlier explorers. US Geological Survey has