SS Edmund Fitzgerald Wreck discovery

Edmund Fitzgerald at the Bottom of the Sea

A U.S. Navy Lockheed P-3C Orion aircraft which is equipped to detect magnetic anomalies usually associated with submarines found the wreck on November 14, 1975. The Fitzgerald lay about 17 miles from the entrance of Whitefish Bay, in Canadian waters close to the international boundary at a depth of 530 feet . A further November 14–16 survey by the USCG using a side scan sonar revealed two large objects lying close together on the lake floor. The U.S. Navy also contracted Seaward, Inc., to conduct a second survey between November 22–25.
Underwater surveys

From May 20 to 28, 1976, the U.S. Navy dived the wreck using its unmanned submersible, CURV-III, and found the Fitzgerald lying in two large pieces in 530 feet  of water. Navy estimates put the length of the bow section at 276 feet and that of the stern section at 253 feet . The bow section stood upright in the mud, some 170 feet from the stern section that lay face down at a 50-degree angle from the bow. The ship's midsection had been reduced to heaps of metal and taconite.

In 1980, during a Lake Superior research dive expedition, marine explorer Jean-Michel Cousteau, son of Jacques Cousteau, sent two divers from the RV Calypso in the first manned submersible dive to the Fitzgerald. The dive was brief, and although the dive team drew no final conclusions, they speculated that the Fitzgerald had broken up on the surface.

The Michigan Sea Grant Program organized a three-day dive to survey the Fitzgerald in 1989. The primary objective was to record 3-D videotape for use in museum educational programs and production of documentaries. The expedition used a towed survey system (TSS Mk1) and a self-propelled, tethered, free swimming remotely operated underwater vehicle (ROV). The Mini Rover ROV was equipped with miniature stereoscopic cameras and wide angle lenses in order to produce 3-D images. The towed survey system and the Mini Rover ROV were designed, built and operated by Chris Nicholson of Deep Sea Systems International, Inc. Participants included the National Oceanic and Atmospheric Administration (NOAA), the National Geographic Society, the United States Army Corps of Engineers, the Great Lakes Shipwreck Historical Society (GLSHS), and the United States Fish and Wildlife Service, the latter providing the RV Grayling as the support vessel for the ROV. The GLSHS used part of the five hours of video footage produced during the dives in a documentary and the National Geographic Society used a segment in a broadcast. Frederick Stonehouse, who wrote one of the first books on the Fitzgerald wreck, moderated a 1990 panel review of the video that drew no conclusions about the cause of the Fitzgerald's sinking.

Canadian explorer Joseph B. MacInnis organized and led six publicly funded dives to the Fitzgerald over a three-day period in 1994. Harbor Branch Oceanographic Institution provided the Edwin A. Link as the support vessel, and their manned submersible, the Celia. The GLSHS paid $10,000 for three of its members to each join a dive and take still pictures. MacInnis concluded that the notes and video obtained during the dives did not provide an explanation why the Fitzgerald sank. The same year, longtime sport diver Fred Shannon formed Deepquest Ltd., and organized a privately funded dive to the wreck of the Fitzgerald, using Delta Oceanographic's submersible Delta. Deepquest Ltd. conducted seven dives and took more than 42 hours of underwater video while Shannon set the record for the longest submersible dive to the Fitzgerald at 211 minutes. Prior to conducting the dives, Shannon studied NOAA navigational charts and found that the international boundary had changed three times before its publication by NOAA in 1976. Shannon determined that based on GPS coordinates from the 1994 Deepquest expedition, "at least one-third of the two acres of immediate wreckage containing the two major portions of the vessel is in U.S. waters because of an error in the position of the U.S.–Canada boundary line shown on official lake charts."

Shannon's group discovered the remains of a crew member wearing a life jacket lying alongside the bow of the ship, indicating that at least one of the crew was aware of the possibility of sinking. The life jacket had deteriorated canvas and "what is thought to be six rectangular cork blocks ... clearly visible." Shannon concluded that "massive and advancing structural failure" caused the Fitzgerald to break apart on the surface and sink.

MacInnis led another series of dives in 1995 to salvage the bell from the Fitzgerald.  The Sault Tribe of Chippewa Indians backed the expedition by co-signing a loan in the amount of $250,000. Canadian engineer Phil Nuytten's atmospheric diving suit, known as the "Newtsuit", was used to retrieve the bell from the ship, replace it with a replica, and put a beer can in the Fitzgerald's pilothouse. That same year, Terrence Tysall and Mike Zee set multiple records when they used trimix gas to scuba dive to the Fitzgerald. The pair are the only people known to have touched the Fitzgerald wreck. They also set records for the deepest scuba dive on the Great Lakes and the deepest shipwreck dive, and were the first divers to reach the Fitzgerald without the aid of a submersible. It took six minutes to reach the wreck, six minutes to survey it, and three hours to resurface to avoid decompression sickness, also known as "the bends".