Scorpion - Season 2 Episode 4 -

The Navy enlists three members of Scorpion on a classified mission in a top-secret submarine 300-feet below the surface. When the crew discover Walter, Happy, and Cabe using comms to communicate with the rest of their team back in the garage, they confiscate and destroy them. But an explosion sends the sub, and everyone on board, to the bottom of the ocean floor with limited oxygen and without any way to get help or notify anyone where they are.