Silent Shark

Silent Shark puts you in command of a U.S. submarine in the WWII Pacific, played tactical-map first: you take hydrophone bearings, plot target motion, and build firing solutions manually in the TDC with tools like the stadimeter. A full Pacific campaign evolves with radio intelligence and historical events, and thermal layers based on actual WWII bathythermograph readings let you hide under temperature gradients. The full game is on Steam for Windows, macOS and Linux, with a free demo playable in the browser.