Sub Battle Simulator (1987) places players in the tense waters of World War II as the commander of an American or German submarine. Across 60 missions, players navigate enemy waters, intercept convoys, and evade aerial and naval threats. The game includes six different submarine types and three gameplay modes: target practice, individual missions, and full war campaigns. Players manage navigation with layered map views, monitor sonar and radar, and consider weather conditions when planning attacks. Combat unfolds both above and below the surface, with a choice between using torpedoes or deck guns—though diving is often safer, especially with enemy aircraft now a threat for the first time in a submarine sim. Developed by Digital Illusions and published by Epyx, Sub Battle Simulator aimed for a mix of realism and accessibility. While praised for its scope and atmospheric tension, reviewers were divided on its simulation depth, with some noting exaggerated visual range and overpowered surface weapons. Still, it introduced important elements that shaped future sub combat games, and stood out as one of the more ambitious naval simulations of its time.

Sub Battle Simulator is another cerebral offering in The Masters Collection.  It’s all about strategy and instrumentation, and seems pretty timeless in its approach to gameplay.  It might make for a welcome intellectual title for modern audiences.