Strait of Hormuz

 The Strait of Hormuz connects the Arabian Sea/Indian Ocean and the Persian Gulf/Arabian Gulf.  Iran lies to the north and the Arabian Peninsula (specifically the United Arab Emirates and Oman) lies to the south.  At its narrowest point, the Strait is 34 miles wide.  For purposes of maritime navigation, a traffic separation scheme (TSS) has been established in order to minimize encounters between large and small vessels and between inbound (west-bound) and outbound (east-bound) traffic.  Inshore traffic zones have been designated for use by smaller vessels.  For larger vessels, such as oil tankers, there are two lanes.  Each lane is two-miles wide and there is a two-mile wide separation median or buffer zone between the lanes.  The lane closest to Iran is for inbound traffic and the lane closest to the Arabian Peninsula is for outbound traffic.  Daily, an average of thirteen loaded supertankers, carrying approximately 17 million barrels of crude oil, pass through the Strait of Hormuz.  The Strait of Hormuz is considered to be the most vulnerable chokepoint for the international transport of oil.  Iran maintains a sizable naval presence in the waters of and near the Strait of Hormuz, consisting mostly of frigates and patrol boats.  Missile installations are also located in the vicinity.  Iran has made threats to close the Strait of Hormuz at various times over the past 30 years, but (to date) has done little more than make threatening gestures toward passing ships.  On December 23, 2011, the US Maritime Administration (MARAD) issued a formal Advisory stating that the potential exists for localized disruption to shipping in the Strait of Hormuz as Iranian maritime forces conduct naval exercises, including boardings and inspections of merchant ships.  If a US-flag vessel is hailed for boarding by the Iranian Navy in international waters, the master should “protest but comply” if circumstances warrant, according to the Advisory.  Due to the navigation constraints, ships passing through the Strait are vulnerable.  On the night of July 28, 2010, the supertanker M Star suffered a terrorist attack while transiting the Strait of Hormuz.  A speedboat with two suicide bombers on board attempted to ram the tanker.  The explosives detonated early, killing the bombers, damaging the tanker, and injuring one crewmember.  A group affiliated with Al Qaeda later took credit for the assault.  Similar attacks can be launched with relative ease.  It would take a significant naval presence in and around the Strait of Hormuz to keep it open to commercial traffic if Iran elected to seriously impede maritime commerce or if terrorists strike again.