drop while others were too far away from the exhausted crew. Against standing orders not to land in open ocean, Marks took a vote of his crew and decided to land the aircraft in swells. He was able to maneuver his craft to pick up 56 survivors. Space in the plane was limited, so Marks had men lashed to the wing with parachute cord. His actions rendered the aircraft unflyable. After nightfall, the destroyer escort , the first of seven rescue ships, used its searchlight as a beacon and instilled hope in those still in the water. Cecil J. Doyle and six other ships picked up the remaining survivors. After the rescue, Marks' plane was sunk by Cecil J. Doyle as it could not be recovered. Many of the survivors were injured, and all suffered from lack of food and water (leading to dehydration and hypernatremia; some found rations, such as Spam and crackers, among the debris of the Indianapolis), exposure to the elements (dehydration from the hot sun during the day and hypothermia at night, as well as severe desquamation due to continued exposure to saltwater and bunker oil), and shark attacks, while some killed themselves. Other survivors were found in various states of delirium or suffered from hallucinations. Only 316 of the nearly 900 men set adrift after the sinking survived. Two of the rescued survivors, Robert Lee Shipman and Frederick Harrison, died in August 1945. Hundreds of sharks were drawn to the wreck by the noise of the explosions and the scent of blood in the water. After picking off the dead and wounded, they began attacking survivors. The number of deaths attributed to sharks ranges from a few dozen to 150. "Ocean of Fear", a 2007 episode of the Discovery Channel TV documentary series Shark Week, states that the sinking of Indianapolis resulted in the most shark attacks on humans in history, and attributes the attacks to the oceanic whitetip shark species. Tiger sharks may also have killed some sailors. The same show attributed most of the deaths on Indianapolis to exposure, salt poisoning, and thirst/dehydration, with the dead being dragged off by sharks. Navy failure to learn of the sinking The Headquarters of Commander Marianas on Guam and of the Commander Philippine Sea Frontier on Leyte kept Operations plotting boards on which were plotted the positions of all vessels with which the headquarters were concerned.