A 12-year-old tourist, Hannah Papps, lost her leg when she was attacked in the same spot while swimming from a yacht the next day.
The 33-year-old victim, Daniel Christidis, was among 10 friends who set out from Airlie Beach on the Queensland state mainland on Monday morning on a rented yacht to sail themselves on a five-day cruise through the idyllic Whitsunday Islands, Police Inspector Steve O'Connell said.
He was savaged while taking turns to paddleboard with a female friend during the late afternoon. Until now, shark attacks in the area had been very rare, a spokesman said.
The bite left the man with critical injuries to his left thigh, right calf and left wrist. "It's just - the injuries were so severe". "They did everything imaginable to try to save the man".
Fisheries Queensland issued a statement at the time of the attacks, warning people that Cid Harbour's waters "are not safe for swimming".
The species of shark has not yet been determined. Paramedics treated him on his boat before emergency crews airlifted him to a local hospital.
"It was one of the more hard ones for everyone involved".
"Every time you have a series of bites, it's usually because of something that's changed within the environment or something that will affect or change the shark's behaviour", Dr Chapman said."A lot of blood, a lot of confusion", he said.
The last shark attack in the Whitsunday Islands before the latest spate occurred on February 13, 2010, off Dent Island where 60-year-old tourist Patricia Trumbull survived lacerations to her buttocks and major blood loss.
"During this holiday period, we urge people to exercise caution, stay out of the water and not throw food scraps overboard from boats", the department said.
Justine Barwick was bitten by a shark at Cid Harbour in the Whitsundays in September.
A shark has killed a man near an island harbor on Australia's Great Barrier Reef where two tourists were attacked on consecutive days in September, officials said.
Professor Colin Buxton from the University of Tasmania told Australian magazine StabMag: "The pros are that drum lines kill sharks and thus reduce the number of sharks in an area and this reduces the statistical chance of a shark encounter with humans".
Tourism Minister Kate Jones says expert advice suggests drumlines are not the most effective method of controlling shark populations.
Temporary signs would be urgently installed and permanent signs would follow deterring people from swimming in the popular anchorage location, according to the statement.