Whanganui doctor Athol Steward swims to protest seabed mining

Athol and Lloyd Steward, centre, reach Kai Iwi Beach after an eight hour swim, flanked by support kayakers Mark Stoneman and Andrew Sclater. Photo / supplied

After eight hours in the water and an epic 20km swim Athol Steward was very glad to reach Kai Iwi Beach on Saturday evening.

The medical doctor and his son Lloyd left Pātea at 10am for the long coastal swim, the second of two aimed to raise awareness and funds and prevent iron-sand being mined from the South Taranaki seabed.

In the water they saw how much life was present. On the first swim, an 11km diagonal cross swum across the proposed mine site on March 20, Steward saw albatross, prions, herrings and snapper and swam through plankton "like a clear soup".

Athol and Lloyd Steward with support during the swim. Photo / Mark Brimblecombe Photography

As he finished the swim a pod of four dolphins gave a victory roll around his safety boat.

On the March 30 coastal swim Steward saw a "boiling" of kahawai, and was buzzed by a friend's small plane. He knows there can be big sharks in those seas, but wasn't worried about them.

He and son Lloyd, 30, had set off from Pātea about 10am, after karakia at Mana Beach. They swam 400 to 1000m from shore, with three kayaks and two boats keeping watch.

They wore wetsuits and stopped every half hour to eat and drink, staying in the water. By the end of eight hours their tongues had swollen from exposure to salt water.

Conditions were "fairly rough", Steward said, with a small swell and "a bit of a chop".

He is hoping news of the two swims will bring donors to a Givealittle page, Making Waves NZ, and raise funds for Kiwis Against Seabed Mining (KASM) to fight the mining proposal.

Mining company Trans-Tasman Resources is seeking to use its consents to suck up millions of tonnes of iron-rich sand from the seabed 22-36km offshore from Pātea. The consents were quashed in the High Court, and the company is looking to an Appeal Court case to overturn that.

The coastal swim was intended to signify that the effects of a mining operation would be felt along the coast, disturbing marine life.

"The strong message for me is that we have got a beautiful, abundant, undisturbed pristine ocean out here. The last thing we want is a massive 66 square kilometre open cast mine," Steward said.

In 2017 he and his sons Lloyd and Jonathan walked from Raglan to Whanganui, 407km, and raised $10,600 for KASM's legal costs.