Manga with shell necklaces and underwater battle suits. Found!

[hidden_kyuubi]

When I was a pre-teen(I'm 25 now) my mom bought me a manga that had a girl that washed up on a beach that this boy and his father(with like no technology/might have been wearing Tarzan-esque loincloth clothings. She had a choker with a shell on it, and the kid asked his dad what it meant and that she was unmarried

Comments

[im_an_aaangel]

Have you checked out Aqua Knight? Seems to fit your descriptions.

[im_an_aaangel]

I should point out that the manga is hard to find but it's been adapted into an anime. Still, if you google "aqua knight manga" you should see some images.

[hidden_kyuubi]

I know a website that has about everything, will go look and let you know.

*ETA* It's not on the site, boo but YES, that was it! Thank you so much it was driving me BONKERS not knowing.