Tim Jago was in charge of coordinating the lifeguard response to the fatal attack, and it was also up to him to formally identify the 46-year-old's body.
He excused himself from the funeral service being held this afternoon at the surf club to give a detailed account of the attack by the two species.
It was important to all involved that the exact chronology of events was put on the record, he said.
The two sharks involved were initially a bronze whaler and then a white pointer, said Mr Jago.
He said Mr Strange had phoned lifeguards at 12.36pm to say he intended to make a training swim a couple of times from Maori Bay to Muriwai's main beach.
Lifeguards saw him complete the first swim, then walk back along the track to Maori Bay.
At 1.15pm Mr Strange entered the water, Mr Jago said. "Almost immediately Adam was subjected to the first of two shark attacks by what we now know to have been a bronze whaler shark.
"It is apparent that Adam unwittingly swam into one or more sharks feeding in shallow waters close to shore.
"Within a very short space of time - 90 seconds - Adam was subjected to a second and fatal shark attack; this time by a white pointer."
Mr Jago said from the extent of Mr Stranger's injuries, his death was almost instant.
The white pointer then carried Mr Strange's body 300 to 400 metres towards the main beach.
Two lifeguards attempted a rescue, driving an inflatable boat into the white pointer and clubbing it with a paddle.
The pair realised Mr Strange was dead and decided it was too dangerous for them to remain because there were other sharks in the area.
Soon afterwards two more rescue craft were deployed and police fired 12 shots at the shark, as it was still "harassing the body".
Mr Jago said an analysis of video footage by emergency services gave him confidence the shark had been killed by the gunfire.
He said he understood there were a number of unique characteristics which had driven interest in the incident.
"Firstly the event was witnessed from start to finish. Secondly there has been a response to try and save Adam, something that's not often possible in shark attacks. Moreover we have Adam back, and that is not often the outcome in such events.
"Thirdly, there has only been one previously documented situation where a white pointer shark has operated in conjunction with a bronze whaler to attack a human."
- Yvonne Tahana of the NZ Herald
