LAKE MICHIGAN - A U.S. Coast Guard oil skimmer sits on the deck of the U.S. Environmental Protection Agency research vessel Lake Guardian as members of the EPA and the Coast Guard prepare to deploy a Coast Guard Vessel of Opportunity Skimming System during an exercise in Lake Michigan near Chicago May 9, 2012. Though permanent vessel alteration is not necessary to use the oil-skimming apparatus, the Lake Guardian is permanently altered to allow for a more rapid response in the event it is ever necessary. (U.S. Coast Guard photo by Petty Officer 1st Class Lauren Jorgensen)