Baffin Bay less than deep near the coast, where the sea bottom is covered with gravel, crushed stone and sand. In the center, there is a deep pit called the Baffin Basin, reaching (see ), which is mostly covered in silt. Currents form a cyclonic circulation. On the eastern periphery, in summer, the West Greenland Current transports water from the Atlantic Ocean to the North. In its western part, the Baffin Island Current brings the Arctic waters to the south. The climate is Arctic with frequent storms, especially in winter. Average January temperatures are in the south and on the north. In
Investigator Strait boundary with Gulf St Vincent is the line from Troubridge Point on Yorke Peninsula to Cape Jervis on Fleurieu Peninsula. Its boundary with Backstairs Passage is the line from Cape Jervis on Fleurieu Peninsula to Kangaroo Head (west of Penneshaw) on Kangaroo Island. Flinders noted that Backstairs Passage is a body of water separate to Investigator Strait. The boundary between the strait and Nepean Bay on the north-east coast of Kangaroo Island is a line between Point Marsden and Kangaroo Head. The Strait’s western boundary by definition is the line from Cape Spencer on Yorke Peninsula to Cape Borda on