Marin, This Serbian, Croatian, Bulgarian, Macedonian, Romanian and also French name means ‘of the sea’. It is a diminutive of full name Marinus and has sweet feminine variations Marina and Marine.
This name is made famous by character Hanna Marin in Pretty Little Liars. And I think this definitely fits within the gender neutral category.
Names reminiscent of Marin include Faris, Aster and Meeri.