Get ready, sailors! Captain Sonar: Upgrade One isn't a whole new game, but rather a souped-up version of the experience you already know and love. If you enjoy the adrenaline rush of commanding a submarine in real-time, with your crew shouting orders and the enemy trying to sink you, this expansion is for you. It introduces five brand-new scenarios that will test your captain and radio operator skills in innovative ways. Additionally, new weapons enter the fray to add that extra spice to battles, and the game now comes with eight erasable markers, making it easier for everyone to trace routes and plan attacks. The novelties don't stop there: Upgrade One also tweaks the rules for the Captain and Radio Operator roles, offering different ways to play and increasing replayability. It's an opportunity to boost your Captain Sonar matches, whether by introducing new tactics or simply to vary the mission menu. Perfect for those who have already mastered the base game and want more challenges, or for those looking to introduce new players with some variations. Team communication and coordination remain the key to victory, but now with an added touch of strategy and surprise. Prepare your ears and sharpen your pencils (or markers!), because the submarine war just got even more intense!