Adm Ali Fadavi, the guard's naval chief, told state TV today that the new weapon would play a "decisive" role in naval wars. He did not elaborate.
The TV showed a short video on launching missiles from under water into the sky.
The Guard launched the drills yesterday near the Strait of Hormuz, through which about a fifth of the world's oil passes. In one exercise, Iranian forces fired at a replica of a US aircraft carrier.
