Something in a lake

An adventure-loving couple convince their friends to explore a remote, uncharted cave system in the forests of Northern Australia. With a tropical storm approaching, they abseil into the mouth of the cave, but when the caves start to flood, tensions rise as oxygen levels fall and the friends find themselves trapped. Unknown to them, the storm has also brought in a pack of dangerous and hungry crocodiles.

A deep cover operative awakens to find himself imprisoned on a submarine. With the help of a fellow prisoner and an amateur agent, he must race against the clock to escape the vessel and expose who set him up.

Researchers on the undersea lab Aquatica have genetically altered the brains of captive sharks to develop a cure for Alzheimer's disease. But there's an unexpected side effect: the sharks got smarter, faster, and more dangerous. After a big storm damages their remote research facility, they must fight for their lives.

The wife of a British Judge is caught in a self-destructive love affair with a Royal Air Force pilot.

Each year the population of sleepy Lake Victoria, Arizona explodes from 5,000 to 50,000 residents for the annual Spring Break celebration. But then, an earthquake opens an underwater chasm, releasing an enormous swarm of ancient Piranha that have been dormant for thousands of years, now with a taste for human flesh. This year, there's something more to worry about than the usual hangovers and complaints from locals, a new type of terror is about to be cut loose on Lake Victoria.

After the events at Lake Victoria, the prehistoric school of blood-thirsty piranhas make their way into swimming pools, plumbing, and a newly opened water park.

When the seaside community of Amity finds itself under attack by a dangerous great white shark, the town's chief of police, a young marine biologist, and a grizzled hunter embark on a desperate quest to destroy the beast before it strikes again.

Police chief Brody must protect the citizens of Amity after a second monstrous shark begins terrorizing the waters.

A group of young explorers discover a secret area hidden from all maps and GPS devices. When they reach the center of the lake, they discover an abandoned facility that houses one of the largest, and deadliest apex-predators known to man.

Man-eating crocodiles return to the lake as two males and one aggressive female crocodile, which is protecting her nest, wreak havoc on the locals.