What is the exact length of a lap of the island?
According to Strava, 3.0 miles. I’m not sure if it’s exactly 3 miles, but probably within +/- .1 of a mile. https://www.strava.com/segments/8436895?filter=overall
It is just about exactly 3 mile. When I create intervals in Golden Cheetah to analyze laps, it lines up best at 4.86 km.