There is no such thing as sea monsters, but there are indeed critters of monstrous proportions that live in the sea. Although jewfish have been closed to harvest for several years now, fishermen and divers still encounter them on a fairly regular basis. Like all members of the grouper family, jewfish love structure - rocks, ledges, culverts, pipes, bridge pilings, shipwrecks and countless others all are potential home to these giants. Please - if you fish or spearfish at all, learn to ID your quarry before you kill it. I've seen quite a few dead and floating small jewfish that were likely a victim of temporary misidentification.
Big jewfish are usually quite friendly around divers.
They're often curious and seem to be interested in what you're doing. It's very tempting to try to feed them, but please beware - that is a big mouth and it does have some teeth. Both diver and fish seem to learn to recognize one another after a few encounters. I'll spare you that old line. Mostly small fish, squid, crustaceans and such.