The project 'The Hatsushima Tokugawa's Shipwreck' relates to investigations conducted by IRIAE in collaboration with ARIUA, between 2016 and 2017, in the seas off the island of Hatsushima (Shizuoka Prefecture) where in 2015 a group of fishermen had reported unusual outcrops on the seabed.

The investigation led to the discovery of a commercial wreck of the kaisen type, i.e. vessels that during the Middle Ages, and especially during the Edo Period (1603-1868), transported goods from north to south along the west coast and from south to north along the east coast.

In the specific case of the Hatsushima wreck, it was immediately evident that the vessel carried architectural building elements such as traditional kawara tiles.

During the investigation activities, however, some architectural elements of inestimable scientific value were brought to light. These were the typical stone lintels called onigawara whose peculiarity was the bas-relief of the mon (coat of arms) of the Tokugawa clan.

Some documents of the period attest to the sinking of a Tokugawa kaisen carrying architectural elements for the restoration of government buildings.

In fact, in 1657, the city of Edo (Tōkyō) and the Tokugawa shōgun buildings were almost totally destroyed by the Mereiki fire. These documents and the data from the investigation of the Hatsushima wreck left no doubt as to the importance of the discovery.

The team of underwater archaeologists from IRIAE and ARIUA worked continuously, in the little time available, to document and survey the wreck, which still retained the wooden entablature beneath the cargo.

The project was realised thanks to the support and funding of the Ministry of Foreign Affairs and International Cooperation of the Italian Republic and the Asahi Shinbun (one of Japan's leading newspapers), which allowed the news to be spread throughout the country.