An ex-detective with a troubled past moves to a small town in northern ireland where he discovers a bad omen by the shores.

Yeh thanks, its not one of my strongest log lines because i haven't actually developed the story yet ! So ill have to work on that

Here's the problem with your logline: You've got a character, you've got an inciting incident but no story so far. What happens when he discovers the omen (whatever it is). What does he have to do?
That's what your logline need.

Hope that helps =)

Gustaf/Storyutbildningen