World's Only Functional Underwater Postbox for Ocean Mail

In the small fishing town of Susami, located in the Nishimuro district of Wakayama Prefecture, Japan, visitors will encounter one of the most unique mailboxes in the world. Situated more than 10 feet below sea level in Susami Bay, this post box is not just any mailing vessel—it is an operational underwater postal service that welcomes divers to drop off their waterproof postcards and letters.

A Quirky Beginning

This extraordinary mailbox was inaugurated on April 24, 1999, during a fair designed to promote the Kumano Kodo pilgrimage routes. The idea was the brainchild of Toshihiko Matsumoto, the postmaster of Susami at the time. Initially conceived as a quirky marketing gimmick, this innovative feature has gained recognition worldwide and holds a place in the Guinness World Record for being the “Deepest Underwater Postbox.”

Operational Details

Operating much like any regular mailbox despite its unusual locale, this sub-aquatic wonder accommodates between one to three collections per day, depending on visitor frequency. Once gathered, these letters or cards undergo standard delivery processes—the only variance being their unique underwater point of origin. To withstand constant submersion and prevent erosion, a special oil-based paint coats the mailbox while an anchor ensures it remains securely stationed against ocean currents.

Visitor Experience

Diving enthusiasts keen to partake in this unique postal experience can obtain waterproof cards and distinctive metal markers from a local store operated by Dive Fair organizers. After drafting their messages on these durable materials, they are ready for submersion into what some might consider an impractical yet thrilling post office adventure inspired by human creativity.

Impact and Influence

Today, approximately 300 to 400 pieces of underwater correspondence find their way into this submerged postbox each year. Despite potential perceptions regarding complexity or inconvenience, for scuba divers visiting Suzami Bay—a postcard dispatched from undersea depths offers unrivaled exhilaration.

As a testament not only to our innovative spirit but also to our enduring affinity for communication across novel mediums, the ‘Underwater Post Box’ remains an integral part of Susami Bay’s cultural tapestry and continues captivating visitors worldwide with its enchanting blend of allure and novelty within Japan’s picturesque coastlines.