Organiser and competitor Alex Martin, of Queenstown, said a "pancake flat" Lake Wakatipu had some entrants worried they would not get their expected tailwind.
However, she was always confident the breeze would pick up, and after delaying the start by 30 minutes until 1pm, paddlers enjoyed an average wind speed of 26 knots on the 17km course, she said.
Open to surf-skis, waka ama and ocean-racing or foiling stand-up paddleboards, the event attracted a record 41 entries, 38 craft making the start line at the Glenorchy marina.
The first paddler to finish was foiling stand-up paddleboarder Liam Walton, of New Plymouth, in 51min 23sec.
Rebecca Cole, of Auckland, won the women’s open ski in 1hr 4min, and fellow Aucklander Gene Prato won the men’s open ski in 1hr 1min.
Three competitors took "swims" — fell off their craft — but were helped back on and finished the course, Ms Martin said.
The event’s nor’westerly course — from Glenorchy to Twenty-Five Mile Creek — was chosen for the second year in a row.
It was one of three courses, all 17km long, set before the event to allow for all possible wind directions, and the final one was selected on Friday after a weather assessment.
"Glenorchy makes for such a fantastic location for this kind of race, because you can pretty much always guarantee the wind comes through."
The sport was steadily growing, especially in the foiling stand-up paddleboard category, in which there were eight entrants.
"They told me they’re going to double the numbers next year, because the conditions are so great."
The average age of entrants this year was 48, with two aged over 70.
Deep South Downwind, which Ms Martin co-organises with the Southern Lakes Multisport Club, is one of eight events in the Darcy Price New Zealand Ocean Surfski series.
