Lisala Folau is now known as "real-life Aquaman" after he swam 7.5km from Tonga's Atatā Island to Tongatapu, following the volcano eruption and subsequent tsunami. 

Folau was reportedly swept out to sea when the tsunami waves first hit the island and, on Saturday (local time), he began a mammoth 28-hour swim to the archipelago's main island. 

He reached the shore of Sopu around 10pm on Sunday, after swimming 7.5km. 

He practically crawled towards the road so that he was able to be found," Marian Kupu of media agency Broadcom Broadcasting, based in Nuku'alofa, told 1News. 

According to Kupu, the man "drifted away and he was holding on to some of the debris caused by the eruption from the islands". 

The man is said to still be in shock following the events of last weekend. 

"Even five days later he was very emotional when he was talking and sharing his experience. I saw some scars on him, on his face and his body. He looks very weak given the conditions and everything," Kupu added. 

New Zealand is one of the nations aiding Tonga following the eruption and tsunami. Earlier on Thursday, the New Zealand Defence Force's Hercules aircraft left Aoteroa for Tonga, filled with urgent aid supplies, including water containers, temporary shelters and generators. 

The Hercules' departure follows the departure of two naval ships that left on Tuesday, with supplies and survey equipment. 

On Thursday, Defence Minister Peeni Henare announced a third navy ship will be sent to Tonga on Friday to aid in the relief efforts following the weekend's eruption of the Hunga-Tonga-Hunga-Ha'apai volcano. 

The HMNZS Aotearoa will take up to 250,000 litres of fresh water and relief supplies. 

HMNZS Canterbury has not been requested yet, but the New Zealand Defence Force's Commander of Joint Forces, Rear Admiral Jim Gilmour, said it was anticipated her capabilities would be required so the vessel is expected to start loading cargo and head off for Tonga tomorrow. 

"This will be not an intention of getting in front of permissions or asks from the Kingdom of Tonga, our thinking is it's much better to get the capability 15 miles off the coast of Tonga and be turned around, than to be desperately required and still here in New Zealand." 

HMNZS Canterbury is expected to depart by Saturday morning at the latest, and should arrive about Tuesday, Gilmour said. It will carry relief supplies, desalination plants, helicopters, and engineers. 

How you can help: To donate to help the people of Tonga, go to: New Zealand Red Cross.