In the making of “Jaws,” the three mechanical models of the shark, collectively known as Bruce, earned a reputation for being notoriously unreliable.

Bruce was a temperamental star of the 1975 Steven Spielberg film, and prolonged breakdowns were a common occurrence.

But the title for most unpredictable shark — mechanical or real — might have just been wrested by another great white, this one named Katharine.

Katharine, all 2,300 pounds and 14 feet 2 inches of her, was tagged with a tracking device on Aug. 20, 2013, off the coast of Cape Cod by a crew from Ocearch, a nonprofit that travels the world facilitating ocean and fish research.