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.
Iran Air Flight 655
As the Strait of Hormuz at its narrowest is wide, in order to traverse the strait, ships must stay within sea lanes that pass through the territorial waters of Iran and Oman under the transit passage provisions of customary Law of the Sea. It is therefore normal for ships, including warships, entering or leaving the Persian Gulf to transit Iranian territorial waters. During the Iran–Iraq War the Iranian forces frequently boarded and inspected neutral cargo ships in the Strait of Hormuz in search of contraband destined for Iraq. While legal under international law, these inspections added to the tensions in the area.