"Graduation ceremony for the Imperial Iranian Navy Submarine Force held in Washington DC in 1978. In the mid 1970's the Imperial Iranian Navy signed a contract to purchase three U.S. submarines from the U.S. Navy. One of these submarines named Kooseh or Shark was purchased for $650,000 with an additional 26 million dollars spent for its complete overhaul. The Imperial Iranian Navy sent their best officers and sailors to the U.S. so they could be trained at a U.S. submarine school. The Iranian officers and sailors spent more that 2 years in Groton Connecticut training side by side U.S. naval officers. Kooseh was delivered to the Imperial Iranian Navy in 1978. It was being prepared for its journey to Iran with its new Iranian crew when the Islamic Revolt took place. The Islamic Republic refused to take the vessel despite the fact that it had already been paid for by Iran. The crew had to return the submarine to the U.S. Navy and return to Iran without the submarine. The U.S. Navy continued to charge the Islamic Republic $70,000 a month to maintain the vessel and eventually seized the submarine as part of the Iranian assets during the hostage crisis. The Submarine was later decommissioned and sold to a company in Florida using it as a research vessel."