  We compare new HERA data for the longitudinal structure function $F_{\rm L}$
with the predictions of different variants of the dipole model. In particular
we show that the ratio $F_{\rm L}/F_2$ is well described by the dipole models
and is rather insensitive to the details of the fit. Fits to $F_2$ are
performed with the help of geometrical scaling (GS). Using the property of GS
we derive the bounds for $F_{\rm L}/F_2$ both for the different versions of the
dipole model and in the general case. Finally we briefly discuss how the higher
Fock components of the photon wave function may affect these bounds.
