“Mermaid Isle” (*1/2 out of four) was a toothless horror thriller about a group of none-too-bright friends (Samuel Buchanon, Kiana Passmore, and others) go to a lake for some fun and sun but end up falling into the lake where a diseased mermaid is on the prowl and this leads to all Hell breaking loose. Ridiculous storyline is played for cheap horror and laughs and winds up drowning in its own absurdities. Almost a horror movie version of “The Little Mermaid” but that probably makes it sound much more entertaining than it really is.