"I was thinking, 'no, no, no, kick out as much as you can'."
The man was blue, his eyes fixed and half open. He appeared to be dead. But still Mr de Saint Germain didn't give up.
"I thought there was a very remote chance we might save him so we have got to do it."
He and his friend Gavin Lee pulled the heavy and waterlogged body to the riverbank. With help from Mr de Saint Germain's partner, Janine Ewan, and Mr Lee's wife, Annie - both trained nurses - they started CPR.
They estimated he had been "dead" for several minutes.
Ms Ewan said they lay him down and she remembered thinking, "We're not going to leave anything behind here." "I was shouting at him, 'Come on, come on, breathe, breathe." It seemed hopeless but then he vomited and water came out of his nose and mouth. "I could feel his heart start beating and he took two to three slow breaths. I was yelling 'Stay with us, stay with us'."
But as the 20-year-old's life was being saved, they were unable to rescue a 22-year-old who had disappeared under the water. Another man, aged 23, was pulled to shore by Mr Lee. All three men in the river were Indian nationals visiting Rotorua.
The dead man's name will not be released by police until his next of kin have been contacted.
The incident unfolded just before 2pm on Monday.
Mr de Saint Germain, a retired airforce pilot who now runs a translation business in Auckland, and Ms Ewan, who manages a hospice in Auckland, were staying at their bach at Rotoiti with their friends Mr Lee, also a retired air force pilot and Mrs Lee, who is now in charge of the emergency department at Middlemore Hospital.
All four are aged in their early 60s.
They were on for a walk when they heard screams for help from an Indian woman at a popular swimming spot. Mr de Saint Germain said they saw two men in the river flapping their arms trying to stay afloat. He and Mr Lee jumped in and grabbed the first man.
As they were pulling him to shore, the Indian woman was yelling at them that there was third man under the water. She pointed to where he went under, about 12m out into the river, and Mr de Saint Germain swam straight there.
Ms Ewan said her heart was pounding because her partner had dived down and couldn't be seen but she was helpless to do anything.
"It all happened so fast. Both of them (Mr and Mrs Lee) were amazing but they are both compromised with their health. Gavin was so courageous. He was a bloody hero. We all just did everything we could."
Mr de Saint Germain said he had been busy saving the 23-year-old man and didn't realise there was one who had gone under. He tried for the next half an hour to find him, along with rafters who had arrived at the scene.
The dead man's body was found nearly two hours later and brought to shore. Mr de Saint Germain and Ms Ewan said they had mixed emotions about what happened. Through tears, Ms Ewan said she couldn't stop thinking about the young man who drowned.
"As a mum, I keep seeing that boy's face . . . we all did everything we could."
Mr de Saint Germain said he had been in contact with Rotorua Hospital because he had hoped to talk to the man they saved.
"The last image of him I had is not nice. For my peace of mind I'd like to see him again."