|At first the racecourse was almost always a straight shot, 235 statute miles up the eastern Michigan shoreline, but in the ‘70s, a 290-mile, two-legged course was introduced, sending the fleet across the lake to the Canadian shore before turning northwest towards Mackinac Island. There were variations on the two themes over the years, but in the early ‘90s, Bayview decided to use both courses, with the smaller, slower boats generally assigned to the Shore Course.
The race has used many different rating rules to handicap its fleets, ranging from the Universal Rule, NAYRU, and CCA, to the IOR, IMS, IRC, and PHRF. In 2016, the Bayview Yacht Club Mackinac Race Authority selected the ORR rule for use by the larger boats on the Cove Island Course and, in 2017, chose ORR-Ez for the Shore Course. ORR requires boat and sail measurements by an independent measurer, with certificates issued by US Sailing, while ORR-Ez uses owner-supplied data and therefore costs less to obtain a certificate.