Star Trek: The Next Generation: Starfleet Academy, book 05 : Atlantis Station
V.E. Mitchell1994

Geordi La Forge and his fellow cadets are headed to Atlantis Station, the underwater research base located near a volcano in the Atlantic Ocean. Up until now Geordi has spent most of his life in space with his Starfleet officer parents and he is more than ready to explore this strange, new world deep underwater.

The first stop for the cadets is the above-ground complex on Isla del Fuego, where the students barely escape a small volcanic eruption. They finally arrive at the underwater station shaken and fighting among themselves, but determined to carry out their assignments.

Then suddenly an earthquake rocks the station and the cadets are trapped in their lab with tempers running high. Now, as debris blocks their path back to the aquashuttle, Geordi and the others, together, must race against time and the dangers of the freezing seawater to escape the station before it disappears into an underwater abyss.