When "Piranha," an in-fish-only remake of the low-budget Roger Corman-produced, Joe Dante-directed original, came to theaters at the tail-end of summer 2010, it was a modest stateside performer, but worked like gangbusters overseas. Less than two years later, it's already become something of a modern camp classic, a gore-, boobs-, and castrated-penis-strewn slasher flick with a sinfully profane sense of humor. As helmed by Alexandre Aja (2008's "Mirrors"), "Piranha" threw together an eclectic cast (among them, Elisabeth Shue, Christopher Lloyd, Ving Rhames, Jerry O'Connell, and Eli Roth) and proceeded to paint the camera lens red with a smorgasbord of gruesome, tongue-in-cheek set-pieces of death at the razor-sharp teeth of prehistoric, man-eating sea dwellers.

In keeping with the whole party atmosphere of these movies, obligatory sequel "Piranha 3DD" has seen its very title become a double-entendre (for those not in the know, it is intended to be read, "Three-Double-D"). With former "Project Greenlight" winner John Gulager at the helm and screenwriters Joel Soisson and partners Marcus Dunstan & Patrick Melton (2010's "Saw 3D") taking over cocktail napkin duties, what we have here is, in actuality, both a little more and a bit less. Whereas its predecessor was humorous but still kept a certain seriousness to its exploits, "Piranha 3DD" fully and unabashedly embraces the silly. As such, the film is eager to please and, at just 70 minutes sans very, very elongated end credits, over before a proper conclusion has been reached. It's just as well, since what comes before this is admittedly a bunch of junky fun.

One year after a deadly piranha outbreak turned the spring break town of Lake Victoria into a desolate quarantine zone, a splashy nearby water park called The Big Wet, owned by the sleazy Chet (David Koechner), is set to reopen in a matter of days. No sooner does Chet's stepdaughter, grad student Maddy (Danielle Panabaker), return to her hometown for the summer that she becomes suspicious another piranha attack might be imminent. With two friends missing and another two injured, Maddy, longtime platonic buddy Barry (Matt Bush), and deputy ex-boyfriend Kyle (Chris Zylka) seek the help of wacky scientist Carl Goodman (Christopher Lloyd). As it turns out, the mutating piranha are migrating through underground rivers and sneaking in by way of the man-made drainage system. Maddy does what she can to warn Chet that danger is headed their way, but before long the grand opening of The Big Wet has turned into a bloodbath.

"Piranha 3DD" is well aware of its own ridiculousness right from the start, what with The Big Wet containing an adult pool area complete with "Cooch Cam" and David Hasselhoff (gamely playing himself) showing up as celebrity lifeguard for the day. A few early scenes do earn fleeting suspense, particularly one where a van carrying nubile couple Ashley (Meagan Tandy) and Travis (Paul James Jordan) ends up rolling into the infested lake. Where the movie charms is in its twisted brand of no-holds-barred comedy. The "Baywatch" theme music is used to terrific effect more than once to underscore Hasselhoff's antics. A young Christian woman about to have unmarried sex gets her praying hands fingered by her boyfriend. Another pretty thing, Shelby (Katrina Bowden), is put through the bloody ringer before bluntly exclaiming, "Josh cut off his penis because something came out of my vagina!" If that weren't enough, Ving Rhames (2009's "Surrogates") reprises his role as a now-legless Deputy Fallon, who just so happens to be at the park for a rehabilitation exercise when all hell breaks loose. Naturally, he has two shotguns on standby that he hooks up to his stumps to blow some nasty piranha ass out of the water.

Low art that nonetheless delivers, "Piranha 3DD" fulfills what it promises: lots of bloody carnage, lots of nudity, and a sweeping helping of spoofery. As lead protagonist Maddy, Danielle Panabaker (2010's "The Crazies") is better than this material, but she at least is a beacon of level-headed sanity amidst the lunacy. Does the picture match the inventiveness of the first film? No. The narrative is even more scattershot than before, and the anticlimactic finale leaves something to be desired. Still, director John Gulager displays a fearless go-getter attitude as he dares to cross the line into bad taste on multiple occasions. How else to explain a closing credits montage set to the lyrics, "Oh, yeah, it's a good day," as the beheaded body of a young child flops around on the ground? The oft-offended should consider themselves warned. This one's for "Piranha" fans only, and they know who they are.