Gaunavou had been visiting the beach with his new teammates when they decided to go for a swim about 4pm.
Flanker Rupeni Tamani noticed Gaunavou crossing his arms, apparently cold from the water. He then tilted forward and fell gently into the water.
Tamani thought Gaunavou was just playing around and expected him to stand up again - but then a wave washed over him, carrying him about 5m away.
Gaunavou was face-down in the water with only his shoulder exposed, and appeared to be shaking as if having a fit.
Another wave came and he was never seen again.
Wairarapa Bush Rugby co-ordinator Doug Bracewell at the time said the worst thing was "not knowing what went wrong with him".
Now Coroner Devonport's report has revealed Gaunavou's death followed a similar incident just five months earlier.
Gaunavou had been swimming in a pool during a Rugby Sevens tournament in Sri Lanka last November when he suffered a seizure.
He was admitted to hospital, where he was diagnosed with epilepsy.
After the incident, his father Banuve Gaunavou warned him not to go into water in case he had another seizure.
Mr Gaunavou has said it was his son's dream to come to New Zealand.
The tragedy cut short a promising career which was on the mend after a frustrating setback.
Gaunavou had been a member of the extended Fijian Sevens squad, but was ruled out of playing in Dubai in 2010 when he fell ill after eating a poisonous fish.
So when Wairarapa's Puketoi Rugby Club sought him out to join the team, Gaunavou was excited at the opportunity to to rekindle his rugby career.
Club president Bruce Bowie has said he was "an exceptional rugby player" with tremendous speed and attributes.
"I haven't seen anybody in these parts who could run as fast as him. And he was exceptional on his feet - he could beat men just at the wink of an eye."
Gaunavou was immensely well-liked by his teammates, who rallied together to search the Wairarapa coast for his body even after the official search was called off.
His body was never found.
