The U.S. Navy is doubling the number of patrol boats it has stationed in the Persian Gulf. Now there will be four of the 170 foot long boats guarding the Iraqi offshore oil facilities from terrorist attack. The navy has 13 of these Coastal Patrol ships (PCs of the Cyclone class). The ships are more like a PT boat than a typical seagoing warship. Cramped conditions on board mean that the crews live in barracks on land when the ships are not at sea. Living conditions for the 28 man crew (four officers and 24 sailors) are austere on these 360 ton ships. When in service, the ships come back to base one a week for supplies. Often a SEAL team or a boarding detachment is carried. But there are rarely more than 36 people assigned to one of these PC class ships. The PCs are not considered boats, but are designated the smallest warships in the U.S. Navy. These ships are normally armed with two 25mm guns and five .50 caliber (12.7mm) machineguns, plus numerous infantry weapons (7.62mm machine-guns and grenade launchers.) Air defense is provided by a shoulder-launched Stinger missile. While many nations mount anti-ship missiles on ships 360 tons or smaller, the U.S. Navy designed the Cyclone class strictly for coastal patrolling. The ships can cross oceans, and have done so whenever distant American naval bases needed additional protection. In the Persian Gulf, the Cyclones have been guarding the Iraqi offshore wells and pumping stations, as well as stopping and inspecting suspicious ships. Crews serve six months in the Persian Gulf, then fly back to the United States. The ships themselves serve at least 18 months before traveling back to the United States. The two ships currently in the Persian Gulf will stay, and be joined by the two that were to have replaced them. The U.S. Coast Guard also has six boats in the Persian Gulf, including four 110 foot ships.