KEY WEST, Fla. (AP) - The Coast Guard is practicing its response to a future oil spill off the Florida Keys. Coast Guard officials say Thursday's exercise will test updates to their regional plan for responding to oil spills off Florida's island chain. In the exercise, oil from a fictitious drilling platform in the Florida Straits threatens to reach the Keys. Coast Guard officials say federal, state and local authorities used lessons learned during the 2010 Deepwater Horizon spill in the Gulf of Mexico to update their oil spill response plans. The updates also address potential risks from exploratory drilling underway in Cuban waters and similar development planned in the Bahamas. Wildlife agencies, law enforcement, researchers and fishermen's associations are joining the Coast Guard in the exercise.