The sun was out, the harbour looked still, and a three-kilometre swim from Petone to Matiu/Somes Island must have appeared inviting.
But a man in his early 20s is likely to be regretting his decision after being flown to Wellington Hospital with hypothermia by the Westpac rescue helicopter.
The man left with two other swimmers and a kayaker from Petone beach about 11.15am.
During the swim, he became separated from the other swimmers and began to struggle. The kayaker stayed with him and pulled him onto the front of his kayak before hailing a passing boat, which took the swimmer to the Matiu/Somes Island dock.
Department of Conservation staff and a visiting off-duty ambulance officer helped to treat him, cutting off his wetsuit and wrapping him in emergency blankets.
He had spent about two hours in the water.
The rescue helicopter was called out to fly him off the island. Crew member Dave Greenberg said the man's body temperature had fallen to about 31 degrees Celsius, making him moderately hypothermic. The normal human body temperature is above 36C.
"He was conscious and starting to warm up," Mr Greenberg said. "He was wearing a wetsuit but I don't know what else. The water was a bit choppy and it wasn't ideal conditions . . . but the other two made it."
The man, from Lower Hutt, was last night discharged from hospital after treatment. He declined to be interviewed.
- The Dominion Post
What should happen with the Zephyrometer?Related story: Wind wand's future up in the air