Harrowing new footage of the fighter jet that crashed into the San Diego Bay yesterday is circulating online ... capturing the moment the craft hit the water.

Check out the new video of the U.S. Navy E/A-18G Growler aircraft ... diving down into the water at full speed and making quite the crash splash as it hit just off the coast of Coronado Island near the San Diego Harbor.

The airplane doesn't slow down at all -- not surprising given the pilots bailed out long before the plane hit the water.

ICYMI ... yesterday video surfaced of the ship in free fall -- though it disappeared behind a building before the actual impact occurred.

San Diego Fire-Rescue later confirmed the two pilots were able to eject from the plane in time ... and, a fishing vessel rescued them from the water. SDFD says the two were then taken to UC San Diego Medical Center for treatment.

The Navy has warned locals to stay away from the crash site area ... and, not to take any debris either from the water or the shore -- telling them to call the local naval base or the authorities if they do spot any debris.

The reason for the crash is still under investigation.