Bathysphere Station

The Bathysphere Station serves as the primary ingress point into Rapture. Bathyspheres from the Lighthouse ferry new arrivals to the Welcome Center complex from this point. Several important elements of BioShock take place here.

History
Every new citizen of Rapture entered through the Bathysphere Station. The station is different from most others in Rapture as it was equipped with two bathysphere docking bays to handle the large influx of expatriates, while still operating normal local bathysphere travel. Just beyond the station is a comfortable Lounge for anyone waiting for the next vehicle's arrival. The Lounge is connected by tunnels to several different points of Rapture's Welcome Center complex.

The station and lounge had previously fallen into disuse when immigration largely ceased in 1952. As life became more difficult in Rapture, People started demanding to return to the surface,  and the Bathysphere Station was the site of large protests.

During the Civil War, Andrew Ryan instituted a lockdown on all bathysphere travel. The covers over both of the bathysphere docking bays were lowered and travel was suspended at the station for unauthorized people. Like most of Rapture, the Station suffered serious damage from the Civil War. At some point, a lone Thuggish Splicer took up residence in the lounge.

BioShock
After descending in a bathysphere from the Lighthouse, Jack arrives in the Bathysphere Station. Before he can begin to appreciate Rapture, he gets his first encounter with the populace. While still inside his bathysphere, he witnesses the Splicer Rose corner and eviscerate Atlas' henchman Johnny. Upon noticing the newly arrived vessel, the crazed woman jumps atop the bathysphere and starts cutting into it in an attempt to get at its occupant. She gives up, after damaging  the vehicle. Atlas, via shortwave service radio, introduces himself and instructs Jack on how to proceed. After some Security Bots scare Rose off, Jack acquires the wrench.

Jack continues on to the Lounge and deals with the splicer living there. He gains the Electro Bolt Plasmid which sends him reeling. In a semi-conscious state, he has a brief encounter with some Splicers and a Little Sister and her Big Daddy. Jack then recovers and journeys on into Rapture.

BioShock Infinite
Destroying the Siphon releases a massive amount of power which embues Elizabeth with total control over her powers. The blast also destroys the Whistler, meaning Booker DeWitt can no longer control Songbird and it's free to attack. However, just before the bird can reach them, Elizabeth transports the three of them to the Lounge area of the Bathysphere Station in Rapture. Elizabeth says an emotional goodbye as the Songbird, on the other side of the window, is slowly drowned and crushed by the enormous ocean pressure. Afterwards, Booker questions Elizabeth about this new, strange location, and she explains that it's "a doorway." The two then proceed down to the station and board a bathysphere up to the Lighthouse.

The station and lounge in the reality that Booker and Elizabeth enter is purposefully different from the one in BioShock. Though largely similar, certain elements and details from the two locations are different, added, or missing and the two games should not be considered as taking place in the same reality. The most noticeable difference is the glass tunnel that connects the station to the rest of Rapture. Here, part of it is gone, likely ripped away by the tail section of Apollo Air Flight DF-0301, and the remaining part is intersected by a new tunnel not present in the first game in which a Little Sister mourns over her fallen Big Daddy.

Behind the Scenes

 * In the Lounge, a pair of chairs block the stairs up to the Gatherer's Garden and they cannot be moved out of the way. As soon as Jack deals the finishing blow to the Toasty splicer, the room shakes, and the chairs fall out of the way. The creators purposefully designed it this way so that the Electro Bolt could not be obtained until after the splicer was killed.