Search continues for SA shark victim

A search is continuing for a 28-year-old spearfisherman believed to have been killed by a shark off the SA coast.

The Adelaide man has been missing since about noon (CDT) on Saturday and witnesses say he was attacked by a shark.

He had been fishing with mates at the popular Goldsmith beach, south of Edithburgh, on the Yorke Peninsula.

The man, a school teacher, was due to compete on Sunday at the 2014 Freedive Extreme York Peninsula Spearfishing Competition, according to The Advertiser.

Competition organiser Jonathan Hammond said the man was the "best bloke you would ever meet" and always had a smile on his face.

"The community is still grasping with what's happened and we're all banding together just to make sure there is support in place for the guys who witnessed it," he told the newspaper.

Sharks were a natural risk when spearfishing and the victim would not want the animal to be hunted and killed, he added.

Police said the search was focusing on the man, rather than the shark, although authorities had little hope of finding him alive.