Iran, apparently with technical help from North Korea, is now building mini-submarines for operations along its coasts, and throughout the Persian Gulf. Two have been built so far. The sub has a two man crew, and can carry three divers, or several naval mines, or a torpedo. The Iranians say they will use the mini-subs to lay mines or launch underwater commando attacks. While the North Koreans provided some technical assistance, the Iranian sub is a local design, smaller than most North Korean mini-subs, which is a reflection of the more turbulent seas found off the Korean coast. In the shallow waters of the Persian Gulf, the Iranian minisubs (which look like an enlarged torpedo, with a glassed over cockpit in the front), can be very difficult to detect. Their range is probably a few hundred kilometers, more than sufficient to reach any targets in the area. However, the United States Navy has spent a lot of time and effort on the problem, and is probably better prepared to deal with minisubs than most navies. North Korea has a fleet of over 60 mini-subs, and apparently Iran wants at least a few dozen.