Minesweeping in Strait of Hormuz could take weeks, sources say Ensuring the Strait of Hormuz is safe from mines could delay a return to normal shipping traffic by weeks, security sources say, even though both Iran and the US enabled some ships to exit the Strait after they negotiated over the interim deal. The operation by conventional minesweepers and state-of-the-art underwater drones could continue for 40 to 50 days before many shipping companies are confident enough to sail through, according to western shipping and maritime security sources who spoke to Reuters. That could potentially hold up tens of millions of barrels of oil, in addition to the oil supply from the Gulf already blocked since the US and Israel attacks on Iran on 28 February, according to estimates based on pre-war flows .