TWO days after a multinational naval coalition to safeguard Red Sea shipping was announced, shipowners are still waiting to hear any operational detail of the plans and are preparing for several weeks of disruption and diversions in the meantime.

Industry associations are waiting for instructions from the multinational Operation Prosperity Guardian before they update any guidance to ships in the area. However, details on the plans remain scant.

On Tuesday, US defence secretary Lloyd Austin announced a coalition involving Britain, Bahrain, Canada, France, Italy, the Netherlands, Norway, the Seychelles and Spain. That has since expanded to 11 states after Greece stated on Thursday that it would send a frigate to support the operation.

But despite the pledges of support from coalition forces, Prosperity Guardian only has four ships currently operating in the area, with the unnamed Greek frigate set to join them at an undisclosed point in the future.

The UK, Italy and France have all deployed warships, but support from other partners is currently limited to administrative and staffing contributions. The Netherlands said it would send two staff officers and Norway said it would send 10 naval officers to Bahrain, the headquarters of the Combined Maritime Forces.

On Wednesday, the EU announced that it was supporting the coalition, effectively opening the door to further support from member states who had previously been reluctant to engage in a mission that had not received formal backing from either Nato or the EU.

While Prosperity Guardian is now expected to expand as more warships make their way to the southern Red Sea, its operations appear limited to coordination of existing naval assets in the region for the moment.

As a result, most container lines that had either paused voyages or already rerouted are not anticipating a return to the Red Sea this year.

As Lloyd’s List reported on Wednesday, several Asia-bound containerships that had stopped in the north of the Red Sea have already returned to the Suez Canal. The fact that carriers are now paying a second canal toll, in addition to the 20 days’ added sailing and a likely additional fuel bill of between $1.5m and $2m, all indicate that the lines are now preparing for the disruption to last many weeks.

Officially, most lines are stating that they are deciding voyages case by case. But privately, industry officials concede that they will not review re-routing until the new year, and, even then, they will need to see what the detail of the naval protection looks like.

Until the rules of engagement for Prosperity Guardian are agreed, tactical details regarding industry best practice guidelines for vessels returning to the region remain unclear. However, security analysts expect that the US is likely to succeed in pulling together a force that will produce a more organised defence of commercial shipping, even as the coalition is nailing down final details.

The operation will likely include either a co-ordinated convoy escort system that clusters merchant ships together to sail with naval protection, or an area security system that attempts to provide a dome-like defence over a wider corridor for commercial traffic, according to analysts at Control Risks.

Depending on the eventual size of the fleet, the force may offer a combination of both, with active escorts provided only for vessels assessed to be at highest risk.

“We are still awaiting details on how merchant shipping should liaise with the navies, and if and how naval operations will shape merchant shipping behaviour and navigation routes,” explained BIMCO’s head of maritime safety and security Jakob Larsen.

However, he also warned that the establishment of Operation Prosperity Guardian could prompt an escalation from the Houthis.

An effective area security system, while degrading the Houthis’ capability to strike vessels with missiles and drones and further boardings via helicopter, could invite the Houthis to deploy other maritime capabilities, including explosives-laden remote-controlled boats.

“The Houthi threat has potential to develop further,” said Larsen. “It cannot be ruled out that the scope of the threat will be expanded further with the establishment of Operation Prosperity Guardian.”

Shipping industry associations have universally welcomed the establishment of Operation Prosperity Guardian as a necessary international response to the threat now faced by international shipping.

Despite the current lack of detail and limited resources, they also remain confident that the naval coalition will be able to impose the required level of security to reopen trade lanes.

“When this mission is shown to be effective, that is what will give the shipowners the confidence to go back through,” said International Chamber of Shipping trade and environment manger John Stawpert.

“When we can see that the Houthis cannot attack successfully, that will reassure shipping sufficiently that trade will go back to something approaching normality in that region.”