Oceanspace — Allen Steele

A novel in which mankind's future lies not among the stars ... but beneath the waves.

It is called Tethys--the first completely self-sufficient undersea research station, situated hundreds of feet below the Atlantic. It is the stepping-stone to a new frontier. Within this oasis of technology are those who seek to unlock the mysteries of the unknown deep. But they are not alone ... Something is stirring from the very depths of the ocean. Something that may be the greatest discovery of all.