The Oceanic Museum (Japanese: 海の科学博物館Ocean Science Museum) is a building built by Captain Stern located in Slateport City. In Ruby, Sapphire, and Emerald, the player must go there to give Captain Stern some parts from the Devon Corporation. When the player first arrives in Slateport, the Oceanic Museum will be inaccessible. The player must first talk to Dock on the first floor of Stern's Shipyard, and then head to the Museum to meet Captain Stern. There are ten people inside the building. A sign outside the museum reads:
"The endless sea sustains all life." OCEANIC MUSEUM
In the games
The player must pay an entrance fee of 50 to enter the museum. One of the Team MagmaROR/Team Aqua GruntsSEAS visiting the museum, the same one that the player had beaten in Petalburg Woods and Rusturf Tunnel, gives the player TM46 (Thief). The Grunt will stay in the museum (even after the player defeats his colleagues on the second floor) until he gives the player the TM and runs off after giving it to them.
The first floor contains information about the sea in the form of seven exhibits. There is also a reporter who asks the player to tell him a story about Pokémon. This report will later be aired on TV.
On the second floor, when the player first visits, they will battle two members of the villainous team. Additionally, this floor has nine exhibits which include models of the Hoenn region and several cruise ships including the Royal UnovaORAS and the S.S. Anne.
Ash and his friends visited the Oceanic Museum in The Spheal of Approval, where they met Captain Stern, who was analyzing rock samples from the ocean's surface. During their visit, Team Magma tried to steal the rock samples, and eventually managed to get away with some, but Captain Stern was fortunately left with a small rock sufficient enough for his research.
The museum can be entered free of charge before Team Magma or Team Aqua leave, as the reception believes that the player is part of their group. However, it only works if the player lacks the 50 fee, which will prompt the receptionist to believe that the player is part of either Team Magma or Team Aqua.