If a shark ever stops swimming, it dies. Dinoshark starts off dead in the water, and lies around for the rest of its agonizing running time, stinking up your DVD player.

It’s going to be really hard for me to describe Dinoshark without getting distracted and talking about other killer fish movies instead. That’s because other killer fish movies are fun to write about, while Dinoshark gives me a headache just by thinking about it. It’s produced by Roger Corman, and originally aired on the SyFy channel, like the much more enjoyable Sharktopus (2010), in which a genetically engineered shark-octopus hybrid broke off its high-tech remote-control collar and wreaked havoc along the Mexican seaside.

Whoops! First distraction! OK, back to Dinoshark. Ugh. So, global warming causes a prehistoric fish to fall out of an iceberg, and it eats an explorer and swims to Mexico. Then it eats some more people, and the good guys talk and talk about how bad the situation is, while the authorities ignore them. Then nothing interesting happens while I stop the disc several times, wondering if I can write this review without finishing this God damn movie.

The monster is supposedly some kind of prehistoric beast. It’s basically a shark with crocodile skin, which doesn’t make it any more interesting than a regular shark. If they made an action figure out of this creature, no kid would buy it because it looks like a piece of driftwood.

Look, I get it. There are a lot of silly killer-fish movies out there. You don’t have to make your killer-fish movie a masterpiece. You don’t even have to make your killer-fish movie original. But making it boring is unforgivable. The fact is none of us have to watch Dinoshark. (Thank goodness.) There are plenty of other sea-monster movies out there, with way more entertainment value than this one. Piranha 3D (2010) has a naked lesbian underwater-ballet scene. The original Piranha (1978) has a good writer (John Sayles), a good director (Joe Dante) and a wrenching but amazing scene in which Paul Bartel’s villain character suddenly turns heroic and risks his life to pull kids out of the water. Sharktopus (2010) has a freaking sharktopus. Mega Shark vs. Giant Octopus has a giant shark leaping out of the water and intercepting a high-flying passenger jet. Frankenfish (2004) has plot twists and an awesome cast of weirdos. Lake Placid (1999) has great lines and interesting characters. Jaws (1975) is an actual masterpiece. People who think that Dinoshark gets a free pass just because it’s a cheap monster movie don’t watch enough cheap monster movies to realize how many better ones are out there.