Solstice: Fury from the Deep

Puck and his friends retire to their spaceship, the Grendel and take off, but it encounters a fault in its navigation system and is jettisoned through space to Onyx in the middle of its oceans, and has landed near a construction base, and the Grendel is brought aboard the base by its tenants and given a warm welcome, but soon, a threat is making itself known, and has emerged from the deepest parts of the sea....