  2$H$-NbS$_2$ is a classic example of an anisotropic multi-band
superconductor, with significant recent work focussing on the interesting
responses seen when high magnetic fields are applied precisely parallel to the
hexagonal niobium planes. It is often contrasted with its sister compound
2$H$-NbSe$_2$ because they have similar onset temperatures for
superconductivity, but 2$H$-NbS$_2$ has no charge density wave whereas in
2$H$-NbSe$_2$ the charge density wave order couples strongly to the
superconductivity. Using small-angle neutron scattering, a bulk-sensitive
probe, we have studied the vortex lattice and how it responds to the underlying
superconducting anisotropy. This is done by controlling the orientation of the
field with respect to the Nb planes. The superconducting anisotropy,
$\Gamma_{ac} = 7.07 \pm 0.2$, is found to be field independent over the range
measured (0.15 to 1.25 T), and the magnetic field distribution as a function of
the applied magnetic field is found to be in excellent quantitative agreement
with anisotropic London theory modified with a core-size cut-off correction,
providing the first complete validation of this model. We find values of
$\lambda_{ab} = 141.9 \pm 1.5 $ nm for the in-plane London penetration depth,
and $\lambda_{c} \sim$ 1 \textmu m for the out-of-plane response. The
field-independence indicates that we are primarily sampling the larger of the
two gaps generating the superconductivity in this material.
