It has taken Tom McClean 20 years and cost him an estimated £100,000 to build the 62-tonne vessel on the banks of Loch Nevis, near Fort William.
Mr McClean, 73, said: “It’s unlike anything I’ve ever done before and it has been a long time coming. Arriving to a huge crowd will be an unbelievable swan-song and my crowning achievement.”
Moby has not moved in three years and the only outings before that were short journeys off the west coast.
Mr McClean, who runs an outward bound centre, plans to refit the boat with new electric motors to replace the reliable but noisy and smelly diesel ones. He wants to completely refurbish the interior, which has a bridge, lounge and bunks for a crew of ten.
“I’ve learned to stick at things when other people might give up,” said Mr McClean, who already holds several records for solo rowing and yachting voyages across the Atlantic. “It makes you feel alive to have a challenge, not just working to pay the bills.”
He has built the vessel in the Knoydart peninsula, one of the most inaccessible parts of mainland Scotland. His isolated home – which he built from scratch – is only accessible by boat or a gruelling seven-mile hike.
He shares his hydro-electricity powered beach-side cottage with Jill, with whom he has two sons, aged 35 and 33.
She is used to his adventurous streak, having waited for him while he became the first man to survive for 40 days alone on Rockall.
“With every project I never want him to do it but he always convinces me he will be fine,” she said. “He convinces me that he has planned it well, and then I end up helping. I have complete faith in him.”
Mr McClean said people often ask him for tips for their own solo crossings, and he tells them to sit in a cupboard for three days and then decide if they still want to do it.
The adventurer – who wants to be buried in Moby – added: “If everything is going wrong can you still do it, can you smile under pressure?”