I'm already seeing some wildly different opinions on this film. Rather than spend time mudslinging the other reviews or accuse them of being "insiders" or fluff, I'd prefer to analyze why. One actually said "if it was an urban legend film it would be good". Okay, so as an "urban legend" film it works, but as a Syfy channel monster movie it doesn't? Either it's good or not and one shouldn't hold the film responsible for their own misperception. Also if you have to resort to claiming that other reviews "were done by people in the production" then that's a surefire sign of your own lack of any discernible writing skill.
On to the film. There is a giant lamprey out there, traveling the world and becoming mythic, and if it comes to your land, you had best give it a willing sacrifice, or there is hell to pay. That is the dilemma this unnamed town is facing, and Victoria, a former resident, is facing an even bigger one. She's been assigned to investigate the mass deaths of marine life that happen to be taking place in the town she grew up in and quickly left. It seems this town is one of those where people just don't do any good with their lives.
Kier and Castor are also residents of the town, both having severe PTSD from participating in the Afghan War (particularly Kier, who is the most frightening character in the film, moreso than the monster, and NOT poorly acted, contrary to one of the other reviews). Now that many years have passed and they're back at home, they're drug runners, and Castor wants local man Callan (yeah the names are a bit strange) to join in as a "mule". Are their actions over the top? Maybe. They do tread a bit of a fine line in regards to depicting servicemen poorly. Whether or not that was the filmmaker's intention is another question, but it makes sense within the film.
Victoria arrives in town and high school sweetheart Kier is not happy about it, and Victoria isn't happy when she accidentally meets up with her father. The scenes between the two actors are NOT what you'd normally expect from this type of film, and are actually surprisingly good and heartfelt, if not a bit strange tonally.
Kier and Castor throw Kier's methhead bootie call into the water to see if there are any monsters about, and there are. There's also a lonely, lost town girl who is like a mini-version of Victoria, obviously in a similar life path. Both characters seem to be there for exposition.
Lamprey-looking creatures are there, but sparingly. You can tell the film had budget constraints, or perhaps moments of "the creature not working". There are far more guns and profanity than there are creatures, and that's fine. The brief action scenes are actually pretty well done, if not also sticking out like a bit of a sore thumb in this type of film.
Despite being a clusterfk of genres, melding a lot of aspects of drama and action that seem out of place at times and some pretty obvious plot holes, Dead Sea isn't a bad late night or mid-afternoon watch. I don't quite understand why a few "cinephiles" who spend more time illegally downloading films feel the need to berate movies like this when they are already the ones doing a disservice to the filmmakers and distributors by STEALING it, but that's another issue altogether.
Review by billperez414 from the Internet Movie Database.