From 1978 through 1980 the race was held on the island of Oahu, the course combining that of three events already held there: the Waikiki Roughwater Swim (2.4 mi./3.86 km), the Around-Oahu Bike Race (115 mi./185.07 km, originally a two-day event), and the Honolulu Marathon. In order to link the end of the bike stage to the start of the marathon course, the bike stage was reduced by 3 miles. In 1981 the race was moved to the less urbanized Big Island, keeping the distances the same: a 2.4 miles (3.86 km) open water swim in Kailua-Kona Bay, a 112 miles (180.25 km) bike ride across the Hawaiian lava desert to Hāwī and back, and a marathon (26 miles 385 yards, 42.195 km) run along the coast of the Big Island from Keauhou to Keahole Point and back to Kailua-Kona, finishing on Aliʻi Drive.
Authors bio is coming up shortly. 