Having deceived the Garmilans to believe that the Yamato was destroyed for sure, and this time armed with the knowledge that the enemy is using a beam weapon that uses satellites, the ship takes the opportunity to stage a counterattack after the recon pilots find the location of the main Garmilan base. It is here that the Yamato engaged in undersea operations--that is, turning the Yamato into Submarine Mode--and shutting down one of the enemy's reflecting satellites, before returning to Ship Mode upon the recon pilot's discovery of the Base...