Cert 15 Stars 3

This tense, atmospheric and claustrophobic sea-going Irish thriller ploughs ahead on strong currents of horror, sci-fi, and fairytales, skippered with a firm and sure hand by Neasa Hardiman on her feature film directorial debut.

When a fishing trawler becomes stranded in a military exclusion zone, a mysterious parasite infects the crew’s precious water supply.

Causing emotional outbursts, psychosis and violence among the increasingly desperate and dwindling crew, they resort to extreme measures to save themselves.

Veterans Dougray Scott and Connie Nielsen play the grizzled captain and his wife who due to being in financial straits, have taken on a fare-paying passenger.

Hermione Corfield is a thoughtful and reserved presence as marine biology student struggling to get her sea legs, but her auburn hair is a red flag to the superstitious sailors.

Taking its name from John Masefield’s evocative poem about the attraction to and obsessive nature of seafaring, the film’s intelligent photography captures the cold beauty and changing moods of the sea, while the scenes of isolation and deadly contagion make for a terrifyingly timely and uncomfortable watch.