This is the most common submarine. It is also the easiest to destroy.
When the submarine reaches the side of the screen, it turns around and continues as before.
The submarine releases standard float mines, .
They move quite fast to the surface where they then disappear.
The standard submarine will try to release a float mine whenever it is underneath your patrol boat, but it will also randomly release mines when it is not directly near you. The standard submarines will become more difficult to destroy further on in the game. They will reload faster and bomb more strategically.
You score between 2,000 and 4,000 points when destroying a standard submarine.