"He may even come up across an oil rig somewhere along the way where they can give him some water over the side or something."
Conditions were good this morning and Mr Donaldson was on the move - now just 213 nautical off the Taranaki coast.
If the weather held, Mr Donaldson could reach New Plymouth in about 10 days, Mr Funnell said.
It wasn't known yet whether the kayak's broken rudder, which had been slowing the trip down, had been repaired.
Mr Donaldson embarked on his journey from Coffs Harbour on April 19, aiming to raise awareness about increasing aerobic activity levels in our daily lives.
It is his second attempt at the crossing.
He has been dropped emergency food and water supplies twice after running dangerously low.