The pair jumped at the opportunity following their impressive results in the Taupo Ironman in March.
Bisley (29), a lifeguard at Moana Pool, finished second in the men's 25-29 category, and McSkimming (40), a business manager, was seventh in the men's 40 to 44 race.
Qualifying for the Hawaiian event on October 10 is no easy task.
The field is limited to just 1700 worldwide, and the Taupo event is the only race of its kind in New Zealand where athletes can qualify.
In Bisley's age group, just five positions were available, and McSkimming was seeking one of nine places.
There is also no time to decide whether to accept the invitation to Hawaii.
Qualifying athletes have to immediately let the organisers know they are going, or right of entry is given to the next-highest finisher.
"We pretty much decided beforehand that if we qualified we'd go," McSkimming said of his Taupo result.
Bisley surprised himself in Taupo with a time eight minutes faster than his 9hr 30min effort on the easier Wanaka course.
McSkimming's time in Taupo was 9hr 46min.
He is hoping to do a similar time in Hawaii, but will be happy with anything below 10hr 30min.
The pair have sought advice from three previous Dunedin representatives in the Hawaii Ironman, Ian Paulin, Kerry Rowley and Mike Adair, who were all quick to remind them that it is the toughest event of its kind in the world.
They have been made aware of the trade winds, renowned for blowing competitors off their bikes on the 180km cycle leg, and the 7km stretch on the 42km run known as the "energy lab" because it draws all the energy from the body in searing 40degC temperatures.
They will also have to overcome the 4km sea swim in water that is 27degC - about the same as Dunedin's Moana Pool, but salty and with waves.
For Bisley, the event may double as a last hurrah in competitive long-course events as his fiancee, Nicky White, is expecting their first child in January, and the couple plan to marry in March.
"We may be able to plan that around the New Zealand triathlon champs," he said.
McSkimming will be accompanied to Hawaii by wife Carmel and son Noah (3), and his parents, Bob and Rowena McSkimming.
Merryn Johnston, from Wanaka, will also compete in Hawaii.
