688(I) Hunter/Killer

688(I) Hunter/Killer is a 1997 submarine simulator game. Developed by Sonalysts Inc. and published by Electronic Arts and more recently by Strategy First, originally for Windows 95-compatible operating systems. It is named after the 688 (Improved) Los Angeles class of United States (SSN) submarine, and was a successor to the earlier game 688 Attack Sub. It is currently available on Valve's Steam content delivery service for Microsoft Windows.