With a lifespan of just 18 months, giant cuttlefish are known to 'live fast and die young'.
For a few months each year about 12km across a bay from steelmaker Arrium's port near Whyalla, lies an underwater natural spectacle.
Diver Tony Bramley has as theory about when he can expect thousands of giant Australian cuttlefish to gather around Point Lowly for their colourful breeding season.
"There's no science to support this, I'm just always of the opinion that they seem to turn up when the water temperature gets below 17 degrees and it was just below that," he said.
With the waters dipping below that magic number, he and other divers surveyed a 40 to 50-metre-square patch at Black Point to see how many were there.
"We saw hundreds of animals in that square and I know it sounds unbelievable but normally when the aggregation is in, a square like that you'd swim over a thousand, maybe more," he said.
"Normally we've got 6km of coastlines with that many animals along it — that hasn't happened yet, but I'm still hopeful."
Mr Bramley said there were enough cuttlefish now to entertain those willing to brave the chilly water, and he said people were always impressed.
"After they get over the initial cold and the discomfort of getting in and out they all universally are amazed at the spectacle."
He said the accessibility of it means anyone can have a look.
For your own view without getting wet, have a look at this video. https://www.facebook.com/100002877626064/videos/vb.100002877626064/852635394842373/?type=2&theater
Read more about these fascinating creatures here.