  We have used the SAURON panoramic integral field spectrograph to study the
structure of the Ly-alpha emission-line halo, LAB1, surrounding the
sub-millimeter galaxy SMM J221726+0013. This emission-line halo was discovered
during a narrow-band imaging survey of the z=3.1 large-scale structure in the
SSA22 region. Our observations trace the emission halo out to almost 100 kpc
from the sub-millimeter source and identify two distinct Ly-alpha `mini-haloes'
around the nearby Lyman-break galaxies. The main emission region has a broad
line profile, with variations in the line profile seeming chaotic and lacking
evidence for a coherent velocity structure. The data also suggests that
Ly-alpha emission is suppressed around the sub-mm source. Interpretation of the
line structure needs care because Ly-alpha may be resonantly scattered, leading
to complex radiative transfer effects, and we suggest that the suppression in
this region arises because of such effects. We compare the structure of the
central emission-line halo with local counter-parts, and find that the emission
line halo around NGC 1275 in the Perseus cluster may be a good local analogue,
although the high redshift halo is factor of ~100 more luminous and appears to
have higher velocity broadening. Around the Lyman-break galaxy C15, the
emission line is narrower, and a clear shear in the emission wavelength is
seen. A plausible explanation for the line profile is that the emission gas is
expelled from C15 in a bipolar outflow, similar to that seen in M82.
