Here is a little video of a small school of Mulloway (jewfish),
The majority of the time that i find these fish they will almost always be up in the wash around some rugged headland. But every now and then you will find them schooling out on some reef off the coast. When chasing Mulloway off a headland i try to use a speargun of around 1m to no longer than 1.2m, although i do have plenty of friends who use a 1.3m speargun. Though when chasing these fish on reefs with clear water i believe that a 1.2 -1.4m gun is ideal.