The victim was with a group of 10 - two of whom were doctors and most had a medical background - who had set sail on a chartered yacht from Airlie Beach, on the north Queensland coast, on Monday morning.
Inspector Steve O'Connell of the Queensland Police Service said: "The group of 10 people were all very good friends and associates on holiday, and a lot of them had a medical background, which meant there were at least two doctors on board, who were able to render immediate first aid". As he dived off the board to make way for his companion, the shark suddenly struck, biting him on the left thigh, right calf and left wrist.
The shark attack occurred while the 33-year-old man was swimming off a private boat with friends on Monday evening in Whitsundays Island region, close to the area where two local tourists had been mauled in separate attacks within 24 hours in September. "It's just - the injuries were so severe", he added.
The husband of one of the September Cid Harbour shark attack victims, 48-year-old Tasmanian woman Justine Barwick, said that the victim's family were in their thoughts. A 12-year-old tourist, Hannah Papps, was attacked in the same harbor the next day, losing a leg.
New Zealand fisherman's ocean rescue of toddler 'miraculous'
A fisherman has saved the life of an 18-month-old boy he spotted floating in the water who he originally thought "was a doll". She said she wanted to warn other parents to zip their tents up tight and consider using a padlock when camping with toddlers.
Prof Colin Simpfendorfer, from James Cook University, said shark attacks were "extremely rare" in the Whitsundays, but no theories had "so far been supported by real substantial information" to understand the spike in shark activity.
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. We simply do not know why this is occurring and what is responsible for it,"Gschwind said".
The species of sharks involved in the attacks have not been identified.
Conservationists argue that drum lines kill sharks unethically, and also harm other marine life.