Ryder Bay is a bay

Bay

A bay is an area of water mostly surrounded by land. Bays generally have calmer waters than the surrounding sea, due to the surrounding land blocking some waves and often reducing winds. Bays also exist as an inlet in a lake or pond. A large bay may be called a gulf, a sea, a sound, or a bight...

 6 nautical miles (11 km) wide at its mouth and indenting 4 nautical miles (7 km), lying 5 nautical miles (9 km) east of Mount Gaudry

Mount Gaudry

Mount Gaudry is a mountain, 2,315 m, rising close southwest of Mount Barre and 5 nautical miles north-northwest of Mount Liotard in the south part of Adelaide Island. Discovered by the French Antarctic Expedition, 1903–05, under Charcot who named it after Albert Gaudry, prominent French...

 on the southeast coast of Adelaide Island

Adelaide Island

Adelaide Island or Isla Adelaida or Isla Belgrano is a large, mainly ice-covered island, long and wide, lying at the north side of Marguerite Bay off the west coast of the Antarctic Peninsula. The island lies within the Argentine, British and Chilean Antarctic claims, at .Adelaide Island was...

. The Leonie Islands

Leonie Islands

Leonie Islands is a group of small islands lying in the entrance to Ryder Bay along the southeast side of Adelaide Island. The French Antarctic Expedition under Charcot, 1908–10, discovered these islands and gave the name Leonie to the largest island. The British Graham Land Expedition under...

 lie across the mouth of this bay. Discovered and first surveyed in 1909 by the French Antarctic Expedition

French Antarctic Expedition

French Antarctic Expedition refers to several French expeditions in Antarctica.-First expedition:Yves-Joseph de Kerguelen-Trémarec was a French explorer....

 under Charcot. Resurveyed in 1936 by the British Graham Land Expedition

British Graham Land Expedition

A British expedition to Graham Land led by John Lachlan Cope took place between 1920 and 1922. The British Graham Land Expedition was a geophysical and exploration expedition to Graham Land in Antarctica between 1934 to 1937. Under the leadership of John Riddoch Rymill, the expedition spent two...

 (BGLE) under Rymill, and in 1948 by the Falkland Islands Dependencies Survey (FIDS). The bay is named for Lisle C.D. Ryder, second mate on the Penola during the BGLE, 1934-37.