Hopes that the world's cruise industry would be gathering steam again in time for the August holiday month are sinking as some ports remain closed and authorities impose new coronavirus health rules.

With the spread of the coronavirus in Europe slowing in recent months many had expected that the height of the Mediterranean cruise season could be salvaged.

The reopening of six key Greek tourist ports on August 1 for cruise ship lines fuelled such hopes.

But Monday's decision by industry leader Carnival Cruise Line to postpone its first cruises in months due to the lack of a green light from Italy shows that many difficulties remain.

On the same day Norwegian operator Hurtigruten suspended its expedition trips after dozens of cases were detected among the crew and passengers after two July cruises on one vessel.

Italy has yet to allow cruise ships to back into Venice and other ports
Italy has yet to allow cruise ships to back into Venice and other ports AFP / ANDREA PATTARO

Norway then slapped restrictions on popular cruises to its fjords, with a second ship ordered into quarantine.

However, Europe's main cruise operators, Costa Cruises and MSC Cruises, are not giving up.

"We are ready, we have worked very hard," MSC's chief Gianni Onorato said Tuesday as the firm presented new health and safety measures.

"We are waiting for the green light from Italian authorities" and "hope to be able to announce some very good news within a few days," he added.

For its part, Costa Cruises, which is part of the Carnival group, told AFP it is "working on plans for a gradual resumption of cruises when the authorities of the home and destination ports say it is possible to do so".

Many of the crew of the Hurtigruten ship Roald Amundsen and several passengers caught the coronavirus during two cruises in July
Many of the crew of the Hurtigruten ship Roald Amundsen and several passengers caught the coronavirus during two cruises in July NTB Scanpix / Terje Pedersen

"There are several signals that seem to be favourable for the second half or even the second week of August," said Erminio Eschena, head of Clia France, an association that groups together the main cruise lines.

Cruise lines have been working hard to develop new health protocols.

They have tried to anticipate each detail with repeated health checks for passengers and crew, as well as beefed-up medical teams.

Costa Cruises' new guidelines say all passengers are subject to a health check as they board and that "all crew members are subject to daily body temperature checks and their state of health is monitored constantly," according to its website.

Nobody wants a repeat of the  Diamond Princess when passengers were forced to endure weeks of quarantine on board
Nobody wants a repeat of the Diamond Princess when passengers were forced to endure weeks of quarantine on board AFP / CHARLY TRIBALLEAU

Meanwhile, MSC Cruises plans daily temperature checks of both passenger and crew and said that physical distancing will be possible thanks to a reduction to 70 percent of passenger capacity.

Both plan to reduce the size of groups for activities.

"The measures taken go beyond the recommendations of bodies such as the WHO or the EU," said Eschena.

But Hurtigruten had testing and quarantine rules in place, which apparently led the ship's doctor to discount the possibility that a crew member had contracted the coronavirus.

"They told me everyone had been tested and all the crew had respected the quarantine rules," the doctor, Karl-Borre Andersen, told Norwegian daily Verdens Gang.

And with the novel coronavirus known to spread in confined spaces national authorities have been skittish.

Many remember the ordeal of the Diamond Princess and its 4,000 passengers as it spent the month of February in quarantine off Japan and the number of infections climbing to 700.

Another fresh memory is the case of the SeaDream 1, a second cruise ship ordered into quarantine by Norway after a Danish passenger who had disembarked several days previously tested positive for the coronavirus.

"We are all shut indefinitely in our own cabins. Room service is going to be busy and there is still 10 days to go" in the quarantine, Rune Vidar Nordum wrote on his Twitter feed.

Champagne and canapes are helping ward away despair for the moment.

"We are well and the captain and crew are taking good care of us," he tweeted, adding a picture of two flutes of bubbly and a plate of mini-sandwiches.

Experts wonder whether the industry will be able to adapt to coronavirus before there is a cure.

"The industry presents a clear risk as have shown certain inextricable situations. And it affects primarily senior citizens who are more fragile," said Didier Arino, head of the Protourisme consulting firm in Paris.

"For an industry which has enjoyed nearly uninterrupted growth for 20 years it is difficult to imagine a real recovery until there is a vaccine," he said.