Ever17: The Out of Infinity

Ever 17: The Out of Infinity is a visual novel video game developed by KID. It is the second entry in the Infinity series; it is preceded by Never 7: The End of Infinity, and followed by Remember 11: The Age of Infinity, 12Riven: The Psi-Climinal of Integral, and Code_18.

From VNDB

"Ever17 is the tale of seven individuals who come to be trapped 153 feet within the underwater marine theme park, LeMU. During an apparently normal day at the park, a massive accident happens, placing almost half of the facility underwater. The path to the surface and the communication lines are cut off.