The MV Reef Spirit set sail from New Plymouth on Monday with the intention of remaining with him to the finish. But conditions became so bad, it was deemed too dangerous for the vessel to stay.
Despite the wild weather, the kayaker remained unfazed, Mr Funnell said.
"He's done three months of it, he's faced these conditions out in the mid-Tasman in the past ... He knows he just has to sit it out."
Conditions were expected to abate by Saturday and Mr Donaldson was expected to reach landfall at Port Taranaki by Sunday or Monday next week, Mr Funnell said.
Mr Donaldson left Coffs Harbour in New South Wales on April 19, hoping to be the first person to kayak solo across the Tasman.