Siobhan (Hermione Corfield) is a brilliant young marine scientist and PhD student who is more at home amidst laboratory equipment than people. She must complete a series of tasks, including a deep sea dive, as a component of her studies, so she hitches a ride on a ramshackle trawler operated by husband and wife Gerard (Dougray Scott) and Freya (Connie Nielsen), whose amiable nature is a mask for financial woes. Charting the vessel into waters forbidden by the coast guard in the hope of a bumper catch, Gerard inadvertently invites the unwelcome attention of a bizarre, bio-luminescent sea creature of unknown origin.

Written and directed by veteran Irish filmmaker Neasa Hardiman, Sea Fever draws us in with its engaging crew of salty characters before ractcheting up the tension through ominous sound design and unsettling creature effects.