Mr Donaldson said there was only a small window of opportunity to retrieve the kayak, as it could run aground on rocks or the beacon may stop transmitting.
"I'm fifty-fifty with it all really, because bad weather is moving in and because of the tracker running out."
Mr Donaldson said he wants the kayak back because of its sentimental value, and the many requests he's had to see the space he lived in for three months.
"She certainly looked after me, and it would be nice to have the thing back ... but I'm not holding my hopes too high," he said.
He had received thousands of emails from people wanting to wish him well, and many from people hoping to hear him speak about the journey, and for that he would need the kayak, he said.
"It sounds like a lot of people want to see the thing and to hear the story."
Mr Donaldson was trying to find details of boats in the area of the kayak and contact them.
Rescue pilot John Funnell, one of Mr Donaldson's supporters, would then fly a plane out to the kayak's location and assist in directing the boat to it.
Mr Funnell said the kayak had sentimental value.
"I think it's a real bit of history for New Zealand."
Mr Donaldson said he had been feeling good since being rescued by helicopter on Friday afternoon.
"Apart from the non-finish it's been good [to be home].
"The body has pulled up really well, but my mind hasn't so well."
He said being at sea for such a long time had left him with sensory deprivation and his mind was feeling sluggish.
*
Salvage at sea:
* Anyone who salvages the kayak may be entitled to claim a reward under salvage law.
* A salvor can only make a claim up until Donaldson or the insurer say they no longer want the kayak -- after that point, "finder's keepers" applies
* The reward is normally calculated on a percentage of vessel's value, as a general rule about 20 per cent, and how dangerous the retrieval was.
(source: Peter Dawson from Dawson and Associates)
