We generalize Conway's approach to integral binary quadratic forms to study integral binary hermitian forms over quadratic imaginary extensions of Q. We show that every indefinite anisotropic form determines a plane ("ocean") in Mendoza's spine associated to the corresponding Bianchi group in the hyperbolic 3-space. The ocean can be used to compute the group of integral transformations preserving the hermitian form. © 2012 Elsevier Inc.
Bestvina, M., & Savin, G. (2012). Geometry of integral binary hermitian forms. Journal of Algebra, 360, 1–20. https://doi.org/10.1016/j.jalgebra.2012.03.017