HELP TO FIND A CERTAIN K DRAMA (you can share the ones you want to find)

hey guys today i had a flashback of a drama and i cant remember the name.
I cant get the thought which drama is it out of my head so please HELP ME!

Its about a girl who lived with her mother in a bookstore i think after her mother dies she later finds her father who is a quite old ex Professor...
Thats it! i hope you can help me! if you want also to find k dramas just share your stories i will help if i can!

There was an amazing Korean drama or movie but I cannot remember its name, and only one scene is stuck in my mind: there was this huge uneven fight with ships, with some amazing manoeuvres, whirlpool and a woman waving from the rocks to warn about a sudden attack from behind!

PLEASE HELP ME if anyone can think of the name!