Iranian has definitely put mines in the Strait of Hormuz because here was one seen off the coast of Oman. According to Open Source Intel, the idea is to divert traffic toward an Iranian-controlled shipping lane:
WILD IMAGE: Iranian mines have reportedly been placed near the Omani coast, threatening the route used by the U.S. Navy to escort merchant ships through the Strait of Hormuz. The apparent goal is to divert traffic toward an Iranian-controlled shipping lane. pic.twitter.com/jm8WDbyoiF
— Open Source Intel (@Osint613) May 31, 2026
Below is a video where you can see the mine floating near the surface of the water: