By Weilun Soon
Jul 13, 2026 (Bloomberg) – Recently, a few ships have quietly passed through the Strait of Hormuz, while visible crossings have almost stopped due to increased fighting between the US and Iran.
According to initial Kpler data analyzed by Bloomberg News, all six commodity carriers that went through Hormuz on Sunday did so with their transponders off. These “dark crossings” were more frequent than visible ones over the last three days.
On Monday, a small tanker identified as part of the dark fleet by a nonprofit organization and a bulk carrier seemed to be trying to cross the strait, based on ship-tracking data from Automatic Identification System signals.
Aside from these few visible crossings, ships have recently been spotted on both sides of Hormuz — in the Persian Gulf or the Gulf of Oman — after they last reported their locations from the opposite side. This suggests that they crossed without turning on their transponders.
Shipowners opting for dark crossings come as the US and Iran engage in tit-for-tat attacks and share conflicting statements about control over the strait. An Iranian foreign ministry spokesperson mentioned on Monday that ships using the US-supported route are at risk.
Visible crossings along the southern route by the Omani coast have completely stopped, with the last passage occurring on Wednesday. In contrast, the northern route, designated safe by Iran, has seen some crossings continue through Saturday.
The recent Iranian attacks on vessels utilizing the Omani corridor, including those with their transponders turned off, seem to have discouraged traffic on that route.
Another option for shipowners is the northern passage, but this would expose them to costs imposed by Iran and potential penalties from the US.
Secret crossings in Hormuz became more common around mid-April when the United Arab Emirates began transporting its oil out of the Persian Gulf on tankers that had turned off their transponders. This move partly explains why the expected oil shortage during the conflict wasn't as severe as initially feared.
Meanwhile, Iran and the US made different statements over the weekend regarding traffic in the strait. Tehran claimed that crossing Hormuz would only be allowed after getting permission from an Iranian authority, while the US Central Command emphasized that there are still open routes for ships to cross freely.
In the past week, Iranian forces have attacked four vessels, all on the northeastern side of Oman’s Musandam peninsula. These incidents suggest that the ships likely followed a US-supported route along the Omani coast. The Islamic Revolutionary Guard Corps announced on Sunday night that it intercepted two vessels considered to be using an “illegal route” that endangered shipping in the strait.