"His kayak is made for the conditions, and the forecast is so bad that everyone agreed it probably wasn't wise to leave that boat there in these conditions, because there's a risk of collision, particularly at night."
Mr Donaldson would "ride out the storm in his kayak", he said.
"He has crossed the Tasman - as he pointed out - without any support."
Strong winds off the coast of Taranaki have already pushed Mr Donaldson back from shore.
The charity paddler was within viewing distance of Mt Taranaki, but poor weather has halted his attempts to make it to land, three months after he set off on his journey.
He has been blown almost 7 nautical miles backwards in 24 hours because of strong winds, placing him around 38 nautical miles west of New Plymouth.
Forecasters have predicted gale force winds for the area as the day goes on, meaning Mr Donaldson is likely to drift at a similar rate away from shore. A drogue has been released from the kayak in an attempt to reduce the effects of the strong winds.
Mr Donaldson has been unable to paddle since Sunday evening, when he was expected to arrive on shore, due to poor weather.
"With the rate of drift he's got, he's probably going to have a good two days of paddling to get back in to Port Taranaki," Mr Funnell said.
"If in fact that's where he actually goes, it may well be that he comes ashore further south, depending on how far south [he's blown]."
Mr Donaldson was still north of the cape of Taranaki, he said, but three days of winds could still push him further south.
The kayaker is not expected to reach Port Taranaki until Friday at the earliest, but it could be well into the weekend before he reaches land.
"It is fair to say Scott has had more than his share of challenges over the last 79 days at sea."
Video: Scott Donaldson in action
He left Coffs Harbour in New South Wales on April 19, hoping to be the first person to kayak solo across the Tasman.
Celebratory plans for his arrival are being handled by Venture Taranaki, who were waiting for the word to set up a huge marquee with entertainment and refreshments next to the New Plymouth Yacht Club at the southern end of Ngamotu Beach.
His wife Sarah and the couple's 4-year-old son Zac are in New Plymouth planning a batch of homemade bacon and egg pie for his homecoming.
