The first book in a trilogy "And the Sea shall give up it's Dead".
Which tells of the long the dark night's in Scotland when the winter and the Icy North Atlantic rage against our shores. It tells of the old dead, all the souls lost to the sea and the sad loss to all still living. such tragedy, such loss needs a god to blame it upon and one, old and dark quickens in the depths, gaining substance and looking for followers. The old sea gods, some still remembered, others long forgotten, have a plan to send this upstart demi-god back from where it came, but they have no power anymore, who pray's to Posidon or Neptune, Scyla or the Sirens anymore, they have no believers and no power. But they do have the creatures that sleep in thier depths. The great whales, the dinosaurs, the sharks and crocodiles of old. Vicious and strong as they are, they will not send the old god god back it's resting place they need someting tougher, more resilient, brutal.