Iranian Fast Underwater Missile 

(Tehran, Iran) Iran has announced the successful test of the "world's fastest underwater missile" designed to destroy surface vessels and submarines.

From IranFocus.com:

"The fastest underwater missile in today's world was successfully tested in the military exercises codenamed Great Prophet," deputy commander of the IRGC Navy Rear Admiral Ali Fadavi told state television, referring to week-long naval war games in the Persian Gulf and the Sea of Oman which began on Friday by Iran's armed forces.

"The speed of this missile called 'Hout' is 100 metres per second and no ship can escape it," Fadavi said, adding that the maximum speed of conventional underwater missiles was 25 metres per second. State television aired clips of the missile as it was being fired and moving in the water.

"Currently, only two countries in the world are equipped with such a missile," he said.

"Ships that can fire the Hout missile are radar-proof and cannot be identified," he added.

The missiles are also designed to evade sonar detection, Fadavi claimed.

To attain a reported speed of over 200 MPH, the weapon must exhaust its fuel rapidly which would tend to indicate it has limited range. Hout apparently translates to whale. Note that the Hout should not be confused with the hooey that is normally discussed in announcements by the Iranians.