Submarine Explorer 1

The Submarine Explorer 1 (Japanese: かいえん  Kaien No. 1) is a submarine built at Stern's Shipyard in Slateport City.

In the games
Team Magma or Team Aqua twice try to steal the Devon Parts, which are parts of the submarine, before the submarine can be built.

After the submarine is completed, Stern reveals that its purpose is to explore the Seafloor Cavern, an underwater cavern on. However, Team Magma or Team Aqua end up stealing the finished product in Slateport City and taking it to the cavern themselves.

In Generation III, the only time the submarine is visible is when it is parked in the entrance of the Seafloor Cavern while the villainous team is inside. In Generation VI, the submarine gets more screentime, being showcased during the theft in Slateport, the preparations at Team Magma Hideout or Team Aqua Hideout, and parking inside the Seafloor Cavern. In these games, the submarine is also modified by the villainous team after it is stolen. It is modeled to look like a or, each team's signature Pokémon, and is equipped with a special drill designed to break the seal blocking the entrance to the Seafloor Cavern.

Inside the Seafloor Cavern, one of the grunts remarks that the submarine is "brutal as a ride" because of its small size. Judging by the number of villainous team members in the Seafloor Cavern, the submarine is able to fit at least seven people. The submarine is not seen again after the player clears the villainous team from the Seafloor Cavern.

In Pokémon Generations
The Submarine Explorer 1 first appeared in The Vision at Team Magma Hideout in its modified state. Maxie, Tabitha, and a division of s boarded the submarine and headed for the Seafloor Cavern.

The submarine appeared again, this time in its Alpha Sapphire guise, in The Cavern. Team Aqua used it to exit the Seafloor Cavern after Archie had awakened Primal. Once they surfaced, Archie was shocked to discover that the devastation Kyogre was causing was far beyond anything that he had planned for.

In the Pokémon Adventures manga
In Pokémon Adventures, two parts of the Submarine Explorer 1 (named the S.S. Kaien 1 in the Chuang Yi translation) are featured: the submarine's "heart", manufactured by the Devon Corporation; and the submarine itself, designed by Captain Stern. Team Aqua steal the submarine's heart in Mowing Down Ludicolo, which enables the submarine to travel deep underwater, while Team Magma steal the submarine itself in Slugging It Out With Slugma II. This eventually leads to the two team leaders forming a pact to temporarily join forces in Walrein and Camerupt, and heading to the Seafloor Cavern together with the complete submarine in Always Keep Whiscash on You for Emergencies. Later, in No Armaldo Is an Island, the submarine breaks apart due to being sent deep underwater without its heart component, and the wreckage floats to the surface.

Name origin
Its Japanese name may come from 海淵 kaien, meaning ocean depths. Its Korean name may come from the equivalent Korean word, 해연 haeyeon.

In other languages
Tiefsee-Forschungsboot 1 Submarino Explorador 1 Sottomarino Explorer 1 海渊１号