“Ghost Shark” 9 p.m. Thursday, Syfy

Not long ago, social media exploded over “Sharknado,” a thoroughly cheesy blend of sharks, a tornado, Ian Ziering, Tara Reid and a now-legendary sequence of a chain saw-carrying Ziering leaping into a giant shark and rescuing a previously consumed woman by carving her out.

Endless replays have followed, along with merchandise, showings of “Sharknado” in movie theaters, and a planned sequel with the fan-recommended name “Sharknado 2: The Second One.”

But Syfy had plenty of crazy shark movies before “Sharknado” and it isn’t waiting for “Sharknado 2” to draw fans back. So welcome “Ghost Shark,” premiering at 9 p.m. Thursday, following a 7 p.m. replay of “Sharknado.”

There’s nothing on the level of Ziering’s chain saw scene in “Ghost Shark.” Nor is the cast as high on the tackiness scale. The notables in “Ghost Shark” are “Night Court’s” Richard Moll and “7th Heaven’s” Mackenzie Rosman; even with Rosman reshaping her image with a Maxim magazine photo shoot, she and Moll combined take up far less space on TMZ than Tara Reid. But when it comes to simple cinematic quality, “Ghost Shark” is on a par with “Sharknado,” just not as hilariously extreme. If you accept “Sharknado” as transcendently terrible, “Ghost Shark” ends up merely terrible.

“Ghost Shark” does have a plot, albeit one that Syfy sums up as: “It’s a shark that’s a ghost. Need anything else?”