Rio's capricious wind has piled further congestion on New Zealand's Olympic rowing campaign.

A second day of the regatta was postponed on Wednesday because of unrowable water conditions, resulting in a shuffling of the schedule.

Four Kiwi crews will face one-day gaps between their semi-final and final, if they qualify, as the last four days get jammed into three.

There were to be four New Zealand boats to contest sudden-death races on Wednesday but they must now wait for what will be a hefty programme on Thursday.


Those are semi-finals of the women's pair and lightweight double sculls, along with the men's and women's eights repechages.

Pair Rebecca Scown and Genevieve Behrent still face the gruelling task of competing in the eight one hour after their race.

If they advance in the pair, they also face just a one-day gap before their final and lightweight double Julia Edward and Sophie Mackenzie face the same scenario.

The others most affected are single scullers Mahe Drysdale and Emma Twigg, whose semi-finals have been shifted a day to Friday. That leaves them with a day to prepare for a final.

The first two Kiwi boats to qualify for finals - men's pair Hamish Bond and Eric Murray and the men's lightweight four - will still race for gold on Thursday. The starting time for both has been moved back an hour.

There have been just two calm days out of five at the inner city venue which is close to the Atlantic Ocean coastline and exposed to breeze from various directions.

If the bad weather continues into Saturday it will complicate the regatta, according to Matt Smith, executive director of world governing body FISA.

"If Friday morning at 10 o'clock we are sitting here, we may have to lose some races," Smith said.