  In "Seshadri fibrations of algebraic surfaces" [arXiv:0709.2592v1] we showed
that if the multiple point Seshadri constants of an ample line bundle on a
smooth projective surface in very general points satisfy certain inequality
then the surface is fibred by curves computing these constants. Here we
characterize the border case of polarized surfaces whose Seshadri constants in
general points fulfill the equality instead of inequality and which are not
fibred by Seshadri curves. It turns out that these surfaces are the projective
plane and surfaces of minimal degree.
