Board Thread:General Discussion/@comment-28172712-20160410032410/@comment-1500935-20160412091837

Troy95 wrote: shuttle crawler is another name for the shuttlebug....also the abandoned bases were also called precursor bases during their development

That explains all, I thought those were supposed to be something different than the abandoned seabases. That means the final base will be near the lava castle, as I don't think those survivors could have gone deeper.