Russian President Vladimir Putin (front) is seen inside a research bathyscaphe while submerging into the waters of the Black Sea as he takes part in an expedition near Sevastopol, Crimea, August 18, 2015. [Photo/Agencies]

MOSCOW - Another summer, another trip to the bottom of a sea for Russia's adventure-loving president.

Vladimir Putin climbed into a three-seat submersible craft Tuesday to check out an ancient sunken ship found recently in the Black Sea off the coast of Crimea. He descended 83 meters (272 feet) to see the remains of the Byzantine trading ship, which he said dated back to the 9th or 10th century.

On previous trips deep underwater, Putin has explored the Gulf of Finland and Lake Baikal in submersibles. He also went scuba diving in the Kerch Strait that connects the Black Sea to the Sea of Azov, where he brought up fragments of ancient Greek jugs, or amphorae, that his spokesman later admitted had been planted.

Speaking by radio to Prime Minister Dmitry Medvedev while still under water, Putin said he hoped the trading ship would shed light on Russia's development and show "how deep our historical roots are".

He told Medvedev he should have come along.