An Evergreen Marine-operated containership that has been blocking the Suez Canal shifted during refloating efforts.

But the move was not enough to refloat the vessel as uncertainty persists over the key waterway's reopening, and it came as the queue of vessels waiting for transit soared well into the hundreds.

An armada of tugs sent to free the 20,388-teu boxship Ever Given (built 2018) were able to move the ship 29 metres by the time efforts were halted on Saturday night, Bloomberg News reported.

Earlier in that day, canal authorities had said the Shoei Kisen-owned ship's propeller and rudder had also been freed from the mud.

But on Sunday morning, the ship remained lodged at kilometre 151 of the canal, where it has been blocking traffic since 23 March.

“Unfortunately, the tidal conditions didn’t help refloating Ever Given,” Leth Agencies said in a tweet.

The efforts came as vessels continued to stack up at the canal's entrances, while the list of ships diverted on longer routes as a result of the closure continued growing.

Leth said on Sunday that there are 327 vessels awaiting at entrances at Port Said and Suez, and some 42 ships are halted within the canal at Great Bitter Lake.

The ships' agency said Suez Canal Authority officials have indicated that once the waterway reopens, they believe they can clear the backlog in one to two days.

Major liner operators, however, have warned that there may still be a ripple effect, with container shipping disruptions lasting after the Suez Canal crisis ends.

Leth said some 14 tugs were involved in the operation on Saturday, in addition to two dredger vessels.

The Ever Given grounded in the canal on 23 March. Photo: Suez Canal Authority

The Ever Given's technical manager, Bernard Schulte Shipmanagement, said that two more tugs were scheduled to join the refloating efforts on Sunday.

The new additions are a pair of powerful anchor handling tugs: ALP Maritime's 24,500-bhp ALP Guard (built 2009) and Augustea Maritime's 10,880-bhp Carlo Magno (built 2006).

Boskalis-controlled SMIT Salvage and Japan's Nippon Salvage are working to free the ship.

On Sunday, Evergreen said 20,000 tonnes of mud and sand have been removed from around the vessel.

“The dredging operation underway has succeeded in loosening the Ever Given’s bow within the bank of the Suez Canal and the ship’s stern has been cleared from the sand bank,” the company said.

“The rudder and propeller of the vessel are fully functional and expected to provide additional support to tugboats assigned to move the containership from the accident site so that normal transit may again resume within the canal.”

Meanwhile, liner operators CMA CGM, HMM Cosco Shipping Lines and Hapag-Lloyd told customers that more ships on their services would be diverted on longer routes around the Cape of Good Hope.

German outfit Hapag-Lloyd told its customers that nine of the company's ships have been affected by the closure, while another six have been diverted around the southern tip of Africa.

Of the diverted vessels, half are on services between Asia and northern Europe, while the other trio are on routes connecting the US east coast to Asia.

Cosco diverts two

Cosco Shipping Lines, the major Chinese operator, said 10 of its ships are impacted by the Suez Canal closure.

The China Cosco Shipping subsidiary said its 13,092-teu Cosco Excellence (built 2012), which is on a service between Asia and the US East Coast, will be diverted around the Cape of Good Hope.

Also rerouted is the 13,386-teu Cosco France (built 2013), which plies a route connecting Asia to northern Europe and the Mediterranean.

A spokesman for South Korean containership operator HMM told Bloomberg that three 24,000-teu containerships are to be diverted around the southern tip of Africa. Two are heading to Europe and the third to Asia.

French liner giant CMA CGM said it diverted two vessels around the Cape of Good Hope.

TradeWinds reported on Saturday that Mediterranean Shipping Co (MSC), the world's largest liner operator, redirected 10 vessels in light of the Ever Given incident. The diversions included several ships in its 2M services with AP Moller Maersk.

For its part, Copenhagen-based Maersk told its customers that 14 vessels on its services were redirected — and that the number is expected to rise. That included ships operated by partners, so some of the vessels mentioned by Maersk were in the ship count in MSC's advisory.

Refloating efforts are scheduled to resume on Sunday after dredging.

Irene Ang contributed to this story.