The Meg (2018)

Naval Captain Jonas Taylor and the expert sea diver five years ago found an unknown danger in the unexplored recesses of the Mariana Trench that forced him to stop his mission and leave half his crew which earned him a dishonorable discharge and cost him his career, his marriage. And any semblance of honor was his unsupported and incredulous claims of what caused it; an attack on his vessel by a mammoth, 70-foot sea creature, believed to be extinct for more than a million years. But when a submersible lies sunk and disabled at the bottom of the ocean - carrying his ex-wife among the team onboard, he gets a call. He must, therefore, must risk his own life to save the crew trapped in a sunken submersible from a 75-foot shark known as the Megalodon.