THE family of shark attack survivor Alistair Raddon have offered a "sincere thank you" to everyone involved, but say the full impact of his injury is still unknown.

The 28 year old had his foot bitten off in a horror double mauling at Hook Passage on Tuesday morning.

His mate Danny Maggs, 22, also suffered a serious injury to his calf as the shark circled back and attacked the two men about 10.17am

"We would like to say a sincere thank you to all that were involved in providing help and rescue to Alistair and Danny on Tuesday," a statement from the family read.

"A special recognition must go to the medical professionals on the boat who acted swiftly and instinctively to ensure both boys made it safely to land and further medical assistance."

The friends, both English tourists, had been wrestling and fooling around in the water after snorkelling at Hook Island while on a day trip to Whitehaven with ZigZag Whitsundays.

It had been the group's first stop of the day. Hook Passage lies about 11km from Cid Harbour where three people were attack, one fatally - by a shark within two months about this time last year.

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Two Swedish nurses, who had been part of the tour, provided lifesaving help during the 20-minute trip to Coral Sea Marina where QAS crews were waiting.

The pair underwent emergency surgery at Mackay Base Hospital and remain in a stable condition.

"We are reassured by his (Alistair's) positive attitude and touched by all the messages of support and kindness that we have received," the statement read.

"The full impact of Alistair's injury is still unknown, and we would appreciate space to deal with the matter privately as a family."