Shark Attack 3: Megalodon

The name of this movie is Shark Attack 3: Megalodon released in 2002-11-26 and it's main theme is When two researchers discover a colossal shark's tooth off the Mexican coast their worst fears surface - the most menacing beast to ever rule the waters is still alive and mercilessly feeding on anything that crosses its path. Now they must hunt the fierce killer and destroy it... before there is no one left to stop it.