HMM: California underwater drone sneaks up on Chinese ‘ghost ship’ off ally’s coast in bombshell video.

Stunning video taken by a covert sea drone shows a Chinese warship lingering inside the Philippines’ exclusive economic zone.

The 42-second clip shows a ship identified by Reuters as a Chinese People’s Liberation Army (PLA) Navy Type 052D guided-missile destroyer, floating 65 miles off Luzon Island in the Bashi Channel on June 16.

The ship was identified by “the deck layout, superstructure, crane and ​mast,” according to the company, “which matched archive imagery.”

Seasats, a San Diego startup, told The Post its drone, the Lightfish USV, was “conducting a commercial operation to prove the feasibility of autonomous operations in the Taiwan Strait.”

Message delivered: You might not even know when you’ve been seen until we choose to tell you.