book about a girl who save a boy stranded on a beach and grows up with him

[Reco]

GENRE is probably teen, honestly cant remember too much since i was 13 or younger when i read it, the latest i could have read it is 2010 -2011.
PLOT its about a girl who finds a boy on a beach and has him live with her for a while and then they go on an adventure together. *SPOILERS* so the whole premise is on this powder that gives people magic and the boy is a prince who had swum from his kingdom to come get help. they learn to use the powder from a fisherman who i think lives in a lighthouse, he teaches the girl to go invisible by whistling a tune while the powder is sprinkled on her, also i think she has a black bird as a pet. the fisherman sprinkles the powder on a harpoon and uses it to pull out some evil creatures submarine or vessel in the final battle. the only thing about the boy i remember is he is a prince and got amnesia when he woke up and that his sister was waiting for him. the premise is about some dark (i think they were literally black) creatures spreading and trying to conquer the land or something.

[Kris]

Reco, can we eliminate Midnight Pearls: A Retelling of The Little Mermaid by Debbie Viguié?

[Reco]

Kris wrote: "Reco, can we eliminate Midnight Pearls: A Retelling of The Little Mermaid by Debbie Viguié?"

although the plot in the beginning seems a little relevant the roles and the later plot are quite different. thank you for the reply though.

[Kate]

Reco ~~
You can "bump" your thread every month or so. This pushes your thread back to the top of the folder instead of languishing here on page 113 where fewer eyes will see it. Get back in the game! Bump!
You can do this by typing a new comment at the end of the thread, or even by typing the word "bump."
Good luck!

[Victoria]

I'd like to bump this post, as I'm trying to help someone find a book with a very similar description!

Additional details from the person I'm helping: "his might be a long shot bc this book is set in england and oldish (probably 70s-80s) but the cover was blue and had portcullis windows with the main characters faces in them (boy and girl) on either side of a central image (can't remember) it might have been the ocean/sea?...the plot is roughly kids are being kidnapped and the boy and girl go to save them with the help of a mariner, his albatross and his submarine! the boy is a fairy i think - he's super pale and has white hair and washed up in the sea side town where the girl lived"

[Victoria]

Bump!

[Becca]

Soul of the Sea by Jasmine Denton, perhaps?

"Mykaela Whindom is rescued from the treacherous seas only to find her best friend didn’t survive the tragic accident. Later, she finds the boy who rescued her wounded on the beach. Her family takes him in and offers him work at their bed and breakfast"

On this cover he has white hair:


If not, it might be worth browsing this list of Teen Mermen Books, or books tagged with 'mermen' on LibraryThing.

[Victoria]

Thanks for the suggestions Becca - I don't believe that's it as the book is apparently from the 70s-80s, unfortunately. The person I was assisting is not interested in pursuing this further I believe, so I'll leave it there. But thank you again!

[Kris]

To avoid confusion, Reco is the OP (original poster).