The 469-foot Sea Diamond sank into the sea after hitting a well-marked and charted reef on Thursday, in fair weather, inside the Greek island of Santorini's sea-filled volcanic crater.
The ship's Greek captain was also charged with breaching international shipping safety regulations and polluting the environment, a Merchant Marine Ministry spokeswoman said.
Another five officers were questioned, but the spokeswoman was unable to confirm a state TV report that they also had been charged. All six were set free, but will provide new testimony next week.
The ship had been minutes away from docking under the spectacular cliffs that make Santorini one of Greece's top tourist destinations. It was carrying 1,154 tourists, most from the United States, and 391 hundred crew members. Dozens of American high school students were among the passengers.
The stricken vessel was evacuated in a three-hour operation, but Jean-Christophe Allain, 45, and his 16-year-old daughter, Maud, from Doue-la-Fontaine in western France were listed as missing, feared to have been trapped in their flooded lower- deck cabin.
A three-day search has found no trace of them; officials said a robot submarine would investigate the hulk - lying more than 330 feet under the water's surface - next week.
The evacuation revived memories of the September 2000 Express Samina ferry shipwreck off the holiday island of Paros, which killed 80 people.
Yiannis Evangelou, the head of Greece's association of travel and tourist agencies, said the Sea Diamond's rescue operation, which he watched from a nearby ferry, was "exemplary." But some passengers complained of an insufficient supply of life vests and life boats, little guidance from crew members and being forced into a steep climb down rope-ladders to safety. Claire Chevrier said she and her friends clung to the deck railing as the ship started sinking. "It was the most horrifying experience in the world. There weren't enough life boats," said Chevrier, an 18-year-old from Boca Raton, Fla., to returned home on Saturday. "We had to walk a plank from the ship to a ferry boat." Passengers said water quickly filled the bottom floors and spilled from the pools. Several people had broken arms, and many passengers didn't even have time to put on shoes after crew members started banging on doors yelling for people to put on their life jackets, Chevrier said. Mindy Hochfelsen said her 18-year-old daughter, Amanda, is diabetic and lost her insulin and syringes. She said the cruise line and the government were not very helpful with people who had health needs. "It was absolutely a disaster," Hochfelsen said. A spokesman for the ship's Cyprus-based operator, Louis Cruise Lines, said the company was working closely with Greek investigators. "We would like to express our deep sorrow over the accident, and our thoughts are with the two missing people and their family," said Giorgos Stathopoulos. "The Sea Diamond was fully up to date with its inspections." The 21-year-old Sea Diamond sank at the end of a four-day cruise, which included visits to the islands of Mykonos, Rhodes, Patios and Crete, and to the Turkish resort of Kusadasi. Tourism officials hastened to play down the potential impact on Greece's vital tourism industry - which accounts for an estimated 18 percent of the country's Gross Domestic Product. "Whoever is responsible for this will be held accountable in the strictest way," Tourism Minister Fanny Palli Petralia said. "Greece is a major tourism destination, and incidents like this must not be allowed to occur. ... Authorities handled the rescue very well." Evangelou said the shipwreck - at the start of a promising tourist season - could put off prospective cruise-goers. "But ... an error by one human being cannot be seen as typical of safety and accident prevention measures in the country." Greek newspapers were critical Saturday in their reporting of the accident. ---- Associated Press writer Kelli Kennedy contributed to this report from Miami. AP-CS-04-07-07 2015EDT