It’s clear that very little money went into this production, yet it manages to be a surprisingly engaging science fiction/horror mystery. The story focuses on the crew of a fishing boat that gets stuck, only to discover a dangerous creature has contaminated their water after they entered an off-limits zone. "Siobhán," portrayed by Hermione Corfield, possesses scientific knowledge and develops a strategy to prevent this deadly organism from eliminating not just the ship’s occupants but also anyone else it might reach. The filmmakers wisely avoid relying on elaborate special effects. The way light is used on the water, combined with some simple visuals of microorganisms, creates enough of an unsettling atmosphere to maintain interest; as do the performances from Corfield, Dag Malmberg, and Olwen Fouéré – and Jack Hickey is quite pleasant to look at! While the writing isn't exceptional, and it feels a bit drawn out, it functions adequately given what they were working with and passes the time acceptably for 90 minutes.

Source on TMDB