This is an add-on for Great Naval Battles. It presents the what-if scenario of various "Super Ships" joining the Battle of the Atlantic. In reality, most of these ships only existed on drawing boards, had only their hulls laid down before being scrapped, or weren't completed until late in the war (or even after its conclusion).
For the German side, the Plan Z ships include the P-Class battleship, the M-Class cruiser, the Z-Class destroyer and the H-Class super battleship. New ships for the British Navy include Lion- and Vanguard-class battleships, Swiftsure- and Bellona-class cruisers and the Battle-class destroyer.
The new ships can be utilized in ten new scenarios, one new campaign, and two new operations.