Originally intended to take the Decepticons back to Cybertron, the Decepticon space cruiser served as their base of operations on Earth. The space cruiser carried many weapons, and its hull was able to withstand the crushing water pressure of an ocean... which is exactly where it ended up. While no longer used actively by the Decepticons, it is maintained as an emergency backup base, and is available for use by those who may wish privacy for their treasonous scheming important research.