  The main result of this paper is an expression of the flag curvature of a
submanifold of a Randers-Minkowski space $({\mathscr V},F)$ in terms of
invariants related to its Zermelo data $(h,W)$. More precisely, these
invariants are the sectional curvature and the second fundamental form of the
positive definite scalar product $h$ and some projections of the wind $W$. This
expression allows for a promising characterization of submanifolds with scalar
flag curvature in terms of Riemannian quantities, which, when a hypersurface is
considered, seems quite approachable. As a consequence, we prove that any
$h$-flat hypersurface $S$ has scalar $F$-flag curvature and the metric of its
Zermelo data is conformally flat. As a tool for making the computation, we
previously reobtain the Gauss-Codazzi equations of a pseudo-Finsler submanifold
using anisotropic calculus.
