Some low-voltage thrillers are so thoroughly predictable as they meander toward an obvious outcome, they generate far more impatience than suspense. Exhibit A: “Dead Water,” a tepid VOD-ready melodrama that strikes faint echoes of Roman Polanski’s “Knife in the Water” and Phillip Noyce’s “Dead Calm” while ponderously padding 60 or so minutes of plot to feature length. Time and again, you may find yourself thinking, “Come on, come on, let’s get going.” And if you’re in the privacy of your home, well, thoughts may inspire irritably spoken words.

It doesn’t help much that director Chris Helton provides little in the way of distinctive visual stratagems or subtly ominous subtext during the long setup for his tale of a weekend yacht cruise that turns deadly. And it doesn’t help at all that, as the host of the excursion, Casper Van Dien is so transparently sleazy from the get-go,...