The Archive.org preservation team has uploaded the official U-Boat Missions ISO.
For , version 1.5 is not a standalone free patch, but rather the version included with the U-Boat Missions expansion . To update your game to version 1.5, you must purchase the U-Boat Missions Add-On or own the Gold Edition . Official Sources for Version 1.5 Silent Hunter 4 1.5 Patch Download