Spithill, who is no stranger to off-shore racing, said this will be the first time he has competed in the iconic Labour Weekend race.
"It looks like a great race and should be a heap of fun," he told Fairfax.
"I've flown helicopters along that coast but always wanted to see it all from a boat. Hopefully we get good breeze."
Spithill has strong pedigree in trimarans.
He holds the unusual record of being the only sailor to skipper a trimaran in the America's Cup, after steering Oracle Team USA to glory in a 2010 Deed of Gift match against Alinghi.
The 90-foot trimaran, nicknamed "DOG-zilla" obliterated the Swiss team, led by Brad Butterworth.
This year's Coastal Classic, which sets off from Auckland's Devonport Wharf and finishes off Russell in the Bay of Islands, is expected to attract a fleet of up to 150 across a range of classes.