Fatal Abyss

Fatal Abyss is a pure underwater 3D combat game, with no complexities of resource management or puzzle solving and an emphasis on a quick-reflex shoot-out near the ocean floor. You can look at the action from many different viewpoints, including both third-person and first-person perspectives. You do have a console map view available showing a 2D relief map of your area as well as a sonar view available showing more clearly which vehicles, structures, and missiles you are approaching.