Shipping traffic rose across both Middle East chokepoints in the week of Aug. 17-23, with Strait of Hormuz transits climbing 27%, while Bab el-Mandeb volumes posted double-digit gains across vessel segments, according to Lloyd's List Intelligence on Thursday.
US sanctions pressure on Iran and Houthi attacks on Saudi-linked vessels kept risk elevated in both waterways.
Preliminary data for the total fleet transiting the Strait of Hormuz indicate 108 transits during the Aug. 17-23 period, up 27% from the previous week.
This marks the highest weekly transit level since the collapse of the interim memorandum of understanding, according to LLI's analysis.
Tanker and gas carrier movements rose over 50% during the period compared with the previous week, driven primarily by non-Iran-linked trade, LLI reported.
The maritime intelligence firm noted that overall vessel volumes remain well below pre-crisis levels and beneath those recorded during the brief memorandum of understanding period.
The week's developments included Washington rolling out a fresh round of sanctions and escalations against Iran, dubbed its "Economic D-Day" package.
In response, Iran's Persian Gulf Strait Authority released a list of 45 ships, including tankers, which the PGSA said had breached unilateral transit regulations.
Ships with connections to the UAE, Greece, and South Korea are on the list. Iran has also warned that vessels conducting ship-to-ship transfers or other business with blacklisted ships could also face sanctions, LLI said.
LLI analysts said the developments have made the bunkering sector "directly exposed to sanctions risk."
"This week's designation of a UAE-based, Greek-owned bunker supplier materially alters the compliance landscape for fuel suppliers, operators and maritime service providers," LLI said.
The maritime data firm said preliminary estimates in the Strait of Hormuz show inbound traffic rose 23% over the week and outbound traffic 32.4% in the Aug. 17-23 window.
"Crude exports continue to move through shuttle tanker and ship-to-ship transfer networks that concentrate risk on a relatively small group of vessels and crews repeatedly operating in high-threat waters," according to the analysis.
This has led to more tankers entering the trade, particularly Gulf state-owned tonnage and vessels linked to South Korea's Sinokor, LLI said.
On the regional outlook, LLI said that Iran continues to pressure vessels using the southern route.
Meanwhile, Iranian officials have maintained that the proposed Iran-Oman framework for the Strait of Hormuz seeks to manage commercial traffic as opposed to freedom of navigation through the Strait.
Additionally, Red Sea shipping traffic also climbed during the period.
In a separate note, LLI's Red Sea Brief showed weekly Bab el-Mandeb volumes also rose over the week in the Aug. 17-23 window.
Tanker traffic increased 13.6%, containership traffic 10%, and bulk carrier traffic 12.2% compared with the prior week.
All categories were up by "double digits, with figures likely to be revised upwards as more dark transits are identified," LLI said.
Saudi-linked vessels continue to be the primary target of Houthi attacks, LLI noted, pointing to the Aug. 24 strike on the Bahri-owned VLCC Amzan off Yanbu.
"The attack fits the pattern established since the Houthis declared a naval blockade on Saudi Arabia on 20 July, with several Bahri-controlled vessels targeted in the weeks since," LLI said, noting that threat levels remain elevated in the region.