On July 2, 1987 the tanker "Glacier Bay" struck a submerged object in Montague Strait and spilled 125,000 gallons of oil. The ship was en route to a refinery in Cook Inlet from Valdez, Alaska, when the incident occurred. "Sedge" was dispatched as the floating command center for the 21 vessels trying to recover the oil. On March 24, 1989, another tanker out of Valdez met a worse fate. "Exxon Valdez" ran aground on Bligh Reef in Prince William Sound spilling of crude oil.  "Sedge" was the first Coast Guard cutter to respond to the scene. An Open Water Oil Containment and Recovery System was embarked and "Sedge" skimmed more than 8,900 barrels of oil from the sea. At various points during the spill response she also conducted shoreline surveys and air traffic control duties. In 1990 "Sedge"s crew constructed the lighted beacon that now marks Bligh Reef.