Islamic Republic of Iran Navy
It is charged with the responsibility of forming Iran's first line of defense in the Gulf of Oman and beyond with the mission of acting as an effective blue-water navy. However, it is generally considered as a conventional green-water navy as it mostly operates at a regional level, in the Persian Gulf and Gulf of Oman but also as far afield as the Red Sea, the Mediterranean Sea and northwest quarter of the Indian Ocean. In July 2016, the Navy said that it would establish a presence in the Atlantic Ocean, of unspecified duration.
2016 U.S.–Iran naval incident
On January 12, 2016, two United States Navy riverine command boats were seized by Iran's Islamic Revolutionary Guard Corps (IRGC) Navy after they entered Iranian territorial waters near Iran's Farsi Island in the Persian Gulf. Initially, the U.S. military claimed the sailors inadvertently entered Iranian waters owing to mechanical failure, but it was later reported that they entered Iranian waters because of navigational errors. The U.S. secretary of state, John Kerry, called the Iranian foreign minister Mohammad Javad Zarif within five minutes. His call was followed by multiple other phone calls between the two ministers. The sailors had a brief verbal exchange with the Iranian military and were released, unharmed, 15 hours later.