US rations air-defence windows for tankers in Hormuz as CENTCOM turns away 99 ships

The United States has asked tankers travelling through the Strait of Hormuz to sail only at specific times in order to guarantee military protection, the Financial Times reported¹. The National carried the same account, that tankers have been asked to sail only during specific time windows to ensure they receive military protection³. Sky News reported that the US is limiting air-defence protection for tankers in the strait².

Separately, US Central Command said its forces had redirected 99 commercial vessels⁵. Arab News reported that CENTCOM said on Friday, in a social media post, that it had forced 99 vessels to alter course amid the blockade of Iran⁶. Khaleej Times reported the same figure of 99 vessels redirected in the ongoing blockade⁴.

Why it matters to investors

Traffic through the strait has thinned to a trickle. Vessels tracked transiting Hormuz fell to seven on Thursday, from 11 the previous day, according to preliminary ship-tracking data reported on Friday⁷. Timed convoys and a naval blockade are not a price signal; they are a physical ceiling on how much crude can leave the Gulf in a given day, and that ceiling now moves with military scheduling rather than with demand.

Middle East Eye reported that the naval blockade comes alongside recently announced harsher economic sanctions on Iran⁵. Arab News noted that the maritime security threat level in the region remained elevated⁶. For shipowners and charterers, the combination sets both the insurance question and the routing question, because a tanker that cannot sail inside a protected window is a tanker that does not sail.

What to watch

Tehran’s terms are shifting. A report from Iran suggests it has changed its stance on tolls in the Strait of Hormuz, according to the semi-official Fars news agency, Sky News reported². Any formalised toll regime would turn a military blockade into a priced one, which is a different problem for cargo owners than an unpredictable closure.

Three measures are worth following from here: the daily count of tracked transits, which has already dropped into single digits⁷; the running total of vessels CENTCOM diverts, last given as 99^4,6; and whether the protected sailing windows widen or narrow^1,3. The National’s coverage ties the same day’s events to President Donald Trump’s assessment that Iran was probably responsible for the attack on the Saudi pipeline³.