The U.S. and Canadian Coast Guards and other state and federal agencies completed a three-day international training exercise Thursday in Ketchikan. The exercise was designed to refine and test the joint emergency response procedures of the United States and Canada during a major pollution incident on waterways shared by both nations. The scenario presented to the group simulated the grounding and discharge of oil into the river from a large merchant vessel. The Coast Guard Cutter Anthony Petit, home ported in Ketchikan, deployed its Vessel of Opportunity Skimming System as part of the drill. The system is designed to be easily deployed from a variety of vessels during an oil spill. A mechanical arm is extended out from the vessels side and trails a boom to gather and retrieve oil.