According to the team’s leader, Tomasz Stachura, the precious goods were on their way to the royal table in Stockholm or the Russian tsar’s residence in St. Petersburg when the ship sank sometime in the second half of the 19th century.

The private group of Baltictech divers, who search for shipwrecks on the Baltic Sea floor, made the discovery on July 11 while checking out interesting spots about 37 kilometers (20 nautical miles) south of the island of Öland. They were ready to call it a day, but two divers, Marek Cacaj and Pawel Truszynski, decided to make a quick dive and surfaced two hours later with news of the wreck and its valuable cargo.

“I’ve been diving for 40 years and it’s not uncommon for us to find a tank or two in a wreck, but finding this much cargo is a first for me,” Stachura told The Associated Press this week.

The brand of mineral water, Selters, which was thought at the time to have medicinal properties, was printed on the ceramic bottles. The brand of champagne has yet to be determined, but the letter R was visible on one cork, Stachura said.

He said he is confident the contents are still in good condition.

“At this depth, the wreck is perfectly preserved, the temperature is constant, there are no currents, and it’s dark,” Stachura said. “That preserves the wreck in a wonderful way.”

He said experts from Champagne and Selters have already contacted Baltictech and are interested in conducting laboratory tests on the contents of the bottles. But it will be the Swedish authorities who will determine the next steps in the investigation into the wreck, Stachura said.

Divers from Baltictech previously discovered the wreck of the SS Karlsruhe, the last ship to leave Koenigsberg in 1945 as part of the evacuation of German citizens during World War II.