The Sea King by C.L. Wilson

He wasn’t supposed to choose her… Seafaring prince Dilys Merimydion has been invited to court the three magical princesses of Summerlea. To eradicate the pirates threatening Calberna and to secure the power of the Sea Throne, Dilys vows to return home with a fierce warrior-queen as his bride. But politics has nothing to do with unexpected temptation.

She didn’t dare wed him… A weathermage like her sisters, Gabriella Coruscate’s gentleness exemplifies the qualities of her season name, Summer. Yet her quiet poise conceals dangerous powers she cannot begin to wield. Better to live without excitement, she reasons, than risk her heart and lose control— until an irresistible Sealord jolts her awake with a thunderclap of raw desire.

Until evil threatens everything they hold dear… When pirates kidnap Summer and her sisters, Dilys is in a desperate quest to save the woman he loves. Only by combining his command of the seas with the unleashed fury of Summer’s formidable gifts can they defeat their brutal enemies and claim the most priceless victory of all: true love.