Nine out of 10 superyacht owners who had work done in New Zealand were visiting the country anyway, Mr Busfield said.
"If we can get them down here as superyacht tourists they'll automatically get work done. At least one of the superyachts in the Millennium Cup has already provided a lot of work for New Zealand," he said.
In total the marine industry was worth about $1.8 billion a year to New Zealand.
Auckland took the lion's share, about two-thirds, with Whangarei and Christchurch second equal with about 10 per cent each. In total the 400-plus cruising vessels and superyachts that visited Northland each year brought the region more than $30 million in foreign exchange earnings.
Holding the cup in Northland boosted the industry's prospects in Whangarei and Opua, he said.
It was also a boon for tourism, with each superyacht spending about $1 million on the likes of accommodation, dining, jet parking and golf.
The race started in Auckland alongside the America's Cup in the year 2000 but was shifted to the Bay of Islands last year in a bid to rejuvenate the event. It was also a great location for sailing, Mr Busfield said. Before the year 2000 few superyachts visited New Zealand. The number leapt to 90 that year before falling away again. It was now back up to 50 and climbing.
The Millennium Cup would return to the Bay of Islands next year subject to support from sponsors such as Far North Holdings, Tourism NZ and the marine industry. This year it brought 220 people to the Bay; Mr Busfield was keen to see numbers boosted to 10 superyachts and up to 400 people. The event is run alongside Bay of Islands Sailing Week.
- The Millennium Cup uses a handicap system based on the yacht's weight, length and sails and conditions on the day, with a staggered start so the boats finish around the same time. This year's overall winner was first-time entrant Tawera, a 28m yacht owned by Aucklanders Mike and Tracy Mahoney. They took part in the race on Silvertip in 2015, and bought the yacht only a month earlier.