Half of the container ship fleet that regularly transits the Red Sea and Suez Canal is avoiding the route now because of the threat of attacks, according to new industry data.

The tally compiled by Flexport shows 299 vessels with a combined capacity to carry 4.3 million containers have either changed course or plan to.

That is about double the number from a week ago and equates to about 18 per cent of global capacity.

The diverted journeys around Africa can take as much as 25 per cent longer than using the Suez Canal shortcut between Asia and Europe, according to Flexport.

Those trips are more costly and may lead to higher prices for consumers on everything from sneakers to food to oil if the longer journeys persist.

The attacks in the Red Sea are being carried out by Yemen-based Houthis, who say they are targeting ships linked to Israel in support of the Palestinians.

But ships without direct links to Israel have also been targeted.

As the escalation of the Israel-Hamas war threatens global trade, a US-led task force is trying to bolster security on the key waterway.

Some ships are trying to broadcast their neutrality as they continue using the route.

Three vessels – two container ships and an oil tanker – are currently traversing the waterway and signalling they have no contact with Israel, according to TankerTrackers.com and ship tracking data compiled by Bloomberg. All three previously called at Russia.

The trend in Flexport’s numbers mirrors a separate count by Swiss freight-forwarder Kuehne+Nagel International that, as at Dec 27, showed 364 vessels with capacity for five million, 20-foot-container units being rerouted around Africa. That compares with 314 vessels on Dec 22.

The figures show the scale of the mounting maritime disruption after Houthis launched more than 100 attacks on commercial ships in the past month. The MSC United VIII container ship was targeted on Dec 26 while en route to Pakistan from Saudi Arabia.

Fifteen container vessels – 10 of them operated by A.P. Moller-Maersk A/S – have either stayed on course or recently abandoned diversion plans in order to cross into the Red Sea towards Suez, according to Flexport’s analysis of data as at Dec 27.

Maersk, the world’s No. 2 container line, said it is preparing to resume Red Sea transits “as soon as operationally possible”. Hapag-Lloyd said it will keep its vessels away from the area even after the launch of a US-led task force to protect the key trade route from militant attacks.

According to Clarksons Research data released on Dec 28, arrivals into the Gulf of Aden declined 40 per cent between Dec 22 and Dec 26, compared with the average for the first half of the month.

Container ship arrivals were down 87 per cent, gas tankers about 30 per cent and car carriers about 25 per cent.

It is a similar picture for Suez Canal transits, which were down about 45 per cent between Dec 22 and Dec 26 for vessels heading south, according to Clarksons.

The diversions around the southern tip of Africa are stretching shipping capacity and boosting freight rates.

Between the Suez diversions and a drought that is limiting maritime traffic through the Panama Canal, the worst-case scenario is a 20 per cent reduction in global capacity, Flexport said.

Bloomberg Economics says that although the US and its partners have successfully intercepted a large share of these attacks, such a defensive strategy is expensive and the risks are still sending shipping insurance higher.

“While the US-led coalition might appear successful militarily, it might not be sufficient for major shipping companies to resume Red Sea transits,” said Mr Gerard DiPippo, senior geo-economic analyst with Bloomberg Economics. “The longer the Houthi attacks continue, the more pressure the US will face to go on the offensive, which risks regional escalation.”

For companies that have cargo on detouring ships, the clamber to track new arrival times is under way.

“That’s happening en masse on every ship that got diverted,” Flexport founder and chief executive Ryan Petersen said in an interview with Bloomberg TV last week. “Teams are working overtime right now to try to keep up with this.” BLOOMBERG