  A blind HI survey of the extragalactic sky behind the southern Milky Way has
been conducted with the multibeam receiver on the 64-m Parkes radio telescope.
The survey covers the Galactic longitude range 212 < l < 36 and Galactic
latitudes |b| < 5, and yields 883 galaxies to a recessional velocity of 12,000
km/s. The survey covers the sky within the HIPASS area to greater sensitivity,
finding lower HI-mass galaxies at all distances, and probing more completely
the large-scale structures at and beyond the distance of the Great Attractor.
Fifty-one percent of the HI detections have an optical/NIR counterpart in the
literature. A further 27% have new counterparts found in existing, or newly
obtained, optical/NIR images. The counterpart rate drops in regions of high
foreground stellar crowding and extinction, and for low-HI mass objects. Only
8% of all counterparts have a previous optical redshift measurement. A notable
new galaxy is HIZOA J1353-58, a possible companion to the Circinus galaxy.
Merging this catalog with the similarly-conducted northern extension (Donley et
al. 2005), large-scale structures are delineated, including those within the
Puppis and Great Attractor regions, and the Local Void. Several
newly-identified structures are revealed here for the first time. Three new
galaxy concentrations (NW1, NW2 and NW3) are key in confirming the diagonal
crossing of the Great Attractor Wall between the Norma cluster and the CIZA
J1324.7-5736 cluster. Further contributors to the general mass overdensity in
that area are two new clusters (CW1 and CW2) in the nearer Centaurus Wall, one
of which forms part of the striking 180 deg (100/h Mpc) long filament that
dominates the southern sky at velocities of ~3000 km/s, and the suggestion of a
further Wall at the Great Attractor distance at slightly higher longitudes.
