Corfu port authorities said some 600 tourists from countries including Italy, France and Germany were on board the Costa Luminosa, operated by Italy's Costa Cruises, and all safety measures were being adhered to in the port. 

Some of the passengers expressed their delight at being able to travel again. 

"It's freedom, enjoying life, you really feel much better. You're not in prison anymore, you're free and that really does you good," said French tourist Robert Maran from Lyon. 

Greece opened its doors on Saturday to tourists from the EU and other key markets such as the United States, Israel and Britain, lifting the need for people to quarantine as long as they have been vaccinated or tested negative for COVID-19. 

Costa's first ship to resume cruises in Greece and the second to restart operations overall, is one of four scheduled to resume cruises this summer in the Mediterranean. 

It set sail from the port of Trieste on May 16, and besides Corfu, will also stop in Athens, Mykonos, the port of Katakolon near Olympia in Greece, and Bari in Italy. It will operate until mid-November for some 27 cruises. 

According to the company website, safety measures due to the coronavirus include a reduced number of passengers, social distancing, testing before embarking and midway through the cruise, as well as daily temperature checks when passengers disembark and re-enter the ship, as well as during excursions. 

Masks will be required when necessary. The crew will also undergo frequent tests. 

Another cruiseship, Mein Schiff 5 with about 1,000 passengers, was the first to dock at Piraeus Port this summer holiday season, Piraeus Port Authority said. 

Tourists visited the local sites on the island wearing masks and underwent temperature checks at the museums. 

"At last we're coming back on track to freedom and work," said tour guide Wafaa Spirou. "Safety and hygiene measures are being respected both by us and by our clients." 

In March, the Costa Luminosa bound for the Italian harbour of Savona, had 36 people on board found to be infected with the coronavirus when tests were undertaken on passengers, during a stop in the French port of Marseille.