Only "Snakes on a Submarine" is scarier than Snakes on a Plane, which is exactly what we get in this claustrophobic, subaquatic thriller starring Luke Perry. Lieutenant Commander O'Neill (Perry) was guiding a retired submarine to its final port when Admiral Wallace (Tom Berenger) diverted the crew for one more mission: to save an army research team from drowning. Lieutenant Commander O'Neill instructs his men to "race silent" in the depths in order to reach the researchers and their top-secret payload while avoiding detection by a hostile enemy fleet. When the cargo turns out to be two genetically engineered leviathans, the hush is quickly broken. Now, deep beneath the ocean's surface, a new predator arises to demonstrate exactly how vulnerable man is when there's nowhere else to flee.