Vogel Sumera

The Vogel Sumera is a highly mobile flying superweapon. It mounts a powerful tectonic reaction beam and can move at over 400 km/h. The easiest way to destroy it (on your first playthrough) is to fire while the superweapon is about to fire the tectonic reaction beam. On your second playthrough, you should have researched better equipment, and you should use a highly mobile ship to evade the superweapon's main gun. A good EM shield will allow your ship to withstand several hits of even the main gun, although a wave gun will not work against this boss. Use heavy cannons to hit it while charging the tectonic beam, it won't move, thus it is an easy target. The treasure is on a southward moving transport on EL1.