"The currents will be neutral, but the wind will push him along. As far as a landing point, we're not sure quite yet, it will depend on the wind direction. He could end up going a little further north than New Plymouth, but we're hoping to have a clearer idea by Thursday next week."
With favourable winds a week ago, Donaldson was covering up to 85km a day.
Donaldson left Coffs Harbour on the New South Wales coast on May 2 and made it to Lord Howe Island in 10 days – a distance of 586km.
Waiting out a storm for seven days, he resumed his journey to New Zealand on May 18, which meant he had been at sea for more than a month.
"I've spoken to him briefly via satellite phone and he is in great spirits, itching to get home."
Donaldson is aiming to make landfall on the Taranaki coast – a distance of 2200km although he will likely paddle 3000km.
With his transtasman kayak attempt, Donaldson was raising funds for asthma research. Donaldson himself is an asthma sufferer.
Follow Scott Donaldson's progress via the website http://tasmankayak.com/