Expect Waves: A Complete Guide to the Mackinac Bridge Swim Adventure
For open water swimmers in the US Midwest or anywhere in the Great Lakes, it's hard to imagine a swim more compelling than the Mackinac Bridge Swim. Crossing the Straits of Mackinac to the Upper Peninsula of Michigan in the shadow of the namesake bridge, straddling Lake Michigan and Lake Huron, is the ultimate bucket list swim.
Date: April 12, 2025
OpenWaterLog had a chance to watch a few intrepid open water swimmers set off at the start of the Mackinac Bridge Swim back in July 2022. This organized event launches swimmers from the northern tip of the mainland “mitten” of Michigan across the narrowest ~5 mile (8km) crossing of the Straits of Mackinac, in the shadow of the namesake bridge, to the state’s upper peninsula. On that perfect summer day with a faintly rippled water surface seen from the shore in Mackinaw City, and Straits of Mackinac water temperature hovering in the low 70sF (~21C), conditions were as inviting as they could be.
But functioning as a spectator rather than a participant that day seemed ideal: the thought of getting all the way to hazy and minuscule St. Ignace, Upper Peninsula was alarming, even for an eager open water swimmer on a day with atypically perfect conditions.
As it happens, the water temperature fell to the high 50’s by the end of the swim in 2022. And 2024 conditions (waves of 2-3 feet) were a more likely best case scenario. The Straits connect Lake Huron and Lake Michigan, which has a complex water flow pattern that changes direction ever ~1.5 days (per the NOAA – Great Lakes Environmental Research Laboratory). Surface water tends to be more turbulent in the Straits than elsewhere in the Great Lakes.
Regardless of what kind of water we get, the view will be different this year. OpenWaterLog will see the start, and hopefully the finish of of the Mackinac Bridge Swim, from the water on July 26. Training, gear choices, and knowledge of open water conditions will be more important than in the average morning swim before work, so OpenWaterLog will revisit and refresh all the best practices:
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Choice of swimming wetsuit and open water swim buoy, which are obligatory at the Mackinaw Bridge Swim,
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What other gear might make a difference in an hours long swim, likely in rough conditions, like the most comfortable swim goggles,
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what other gear would be helpful (a waterproof phone case for taking photos from the water),
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How to characterize typical conditions in the Straits,
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Training choices: how much open water swimming is enough to complete a 5 mile swim (which will be a first for us); how much and what kind of rough condition training is needed match the expected conditions (open water swimming temperatures, wave heights, and wave periods) that day,
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Open water swimming safety measures and guidelines.
More to come!