What You Need to Know About the Swim


NOTE:  Important event information will be communicated to swimmers through our Facebook page, Facebook group and e-blasts.          Please do not unsubscribe to our e-blasts.  If you receive an email from us, it will be important ... we promise.  Thank you!

For what you need to know about lodging ... see "Discounts" Page  

Rainbow on Mighty Mac Swim course
Sun shines through ominous clouds on Mighty Mac Swim course

Crossing the Straits of Mackinac next to the iconic Mackinac Bridge showcases Pure Michigan beauty at its' finest.  The beauty however, can also be a beast. 


The challenges presented in crossing the Straits of Mackinac make successfully finishing the Mighty Mac Swim a crowning achievement. While these challenges will always make themselves known to various degrees, they normally will be overcome by a well-trained swimmer in all but the worst conditions, resulting in a successful finish.  That said, participants should enter the Mighty Mac Swim with eyes wide open.  

The Straits of Mackinac is approximately four statute miles across as the crow flies.  However, swimmers should expect to take longer to swim distances in the Straits than they are normally accustomed and with greater effort, due to cross-currents that vary in direction and intensity.   Each stroke will often pull a swimmer trying to stay on course diagonally as well as forward.  Water temperatures are likely to range anywhere from the mid-50's to the upper-60's (degrees Fahrenheit). 

While the quests are very different, and while it might seem bold to make this

comparison, there are some parallels to planning a swim across the Straits of

Mackinac and planning an ascent on Mt. Everest.  To climb Mt. Everest, you not only

need to be a skilled mountaineer, you must also have some luck.  That is, you must

have the cooperation of Mother Nature.  The best climber in the world will not summit

in a blizzard.  Likewise, while many are capable of swimming the Straits, the best

swimmers will not beat Mother Nature’s currents at their worst here (if they should

occur).   Now add to the challenge, attempting to pin down Mother Nature’s

cooperation to a single morning.  Mighty Mac Swim participants should understand

that success rates may vary considerably from year to year, and finishing the swim on

any given year may or may not be in the cards.  Please read the information below

thoroughly, and embrace this swim for the challenge it represents … even if it

becomes a multi-year quest for you.  That will make victory all the sweeter!    

If this quest sounds appealing, THIS is the swim for YOU!


To prepare for swimming the challenging Straits of Mackinac, Download a Sample Training

Schedule & FAQs HERE.  Download a Training Strategy Document HERE.

You Should Know the Following Before You Register



1.  Age Requirement:  Swimmers must be at least 18 years of age on the date they REGISTER to enter the Mighty Mac Swim. 

2.  Qualification Requirements:  The Mighty Mac Swim is intended only for experienced open water swimmers.  To enter, swimmers warrant that they have routinely completed continuous swims of at least 1 mile in the open water within the past year and can currently keep a pace of 45 minutes or less per mile swimming in the consistent environment of a pool.  Entrants pledge that they are capable, or will train and become capable, of swimming 4 continuous miles in the open water (allowing nutrition breaks), while maintaining a minimum 45-minute mile pace or less in relative pool-like conditions, prior to participating in the Mighty Mac Swim.

3.  Currents & Required Pace:  Cross currents are always a factor, to varying degrees, when swimming the Straits of Mackinac and can range from having little effect to being overpowering.  As a general guide, while a swimmer can mathematically complete the 4+ mile swim in the 4-hour time allotted by keeping a pace of just under 60 minutes per mile, a swimmer should be capable of keeping a 45-minute per mile pace in a swimming pool, at the very minimum, before considering entering the Mighty Mac Swim.  While this pace is the minimum standard, the Straits of Mackinac can produce currents capable of overpowering any swimmer’s forward progress or ability to stay on course, regardless of their normal pace.  See #12 below for details on disqualification due to swimming pace and the effect of the currents.

4.  Mandatory Gear


Wetsuits, swim buoys and whistles are requirements of our U.S. Coast Guard permit.


  • Wetsuit:  Wetsuits are mandatory to participate in the Mighty Mac Swim.  This uncommon requirement is due to specific challenges faced when 400 participants without 400 dedicated escort boats swim the Straits of Mackinac, and considers more than just water temperatures (which is actually a secondary consideration).  The wetsuit policy is necessary mainly due to the unpredictability in the strength of the currents.  Currents will have swimmers in mid-50 to upper-60-degree (Fahrenheit) water temperatures longer than it would normally take them to swim 4 miles.  This would still not mandate wetsuits in reasonable currents.  However, the wetsuit policy is based on a worst-case mass rescue scenario.  The currents are capable of changing quickly without warning and can be overpowering for even the best swimmers.  If a great number of swimmers were swept off course, some may spend an extended period of time at sea.  Rescue would be coming immediately, but it may take a while before the fleet of rescue boats are able to pull all drifters from the water.  While this scenario is viewed as a highly remote possibility, the Straits of Mackinac has proven to possess this kind of power.  Our safety policies will always plan for the worst, no matter the likelihood. 


           Wetsuits must be 1-piece.  Wetsuits may be long-sleeved, short-sleeved or sleeveless.  Pant legs may be full-length or short.   


           A 50% discount on wetsuits is provided to Mighty Mac Swimmers by Aquaman.  

  • Swim Buoy:  Towing a brightly colored open water swim buoy/dry bag is mandatory in order to participate in the Mighty Mac Swim.  The Straits of Mackinac is an entirely different animal, requiring us not to allow anyone to swim without one!  If you do not already own a swim buoy, it is your responsibility to supply this item.  Aquaman provides a 20% - 50% discount on buoy/dry bags and other accessories to Mighty Mac Swimmers.  Don’t forget to make this purchase (if necessary) and bring it with you!  If you are a serious open water swimmer, you will want one of these anyway.   Not only is the swim buoy/dry bag a great safety device, keeping you visible and giving you a flotation device to cling to in an emergency, you can carry items with you, such as nutrition, extra goggles, shirt, cell phone, etc.

           See Using Your Swim Buoy for more information on safety, packing and feeding.        


           NOTE:  It is also a requirement to write your name on the outside of your swim buoy.   Please make sure you tighten the belt securely

           around your waist, so you don’t lose your buoy during the swim.  Swimmers without buoys must be extracted.    

  • Whistle:  A USCG-approved rescue whistle will be provided to swimmers in race packets.  You are required to have this with you when you are swimming and readily available for use (i.e. attached to buoy/dry bag).

  • Swim Cap:  Swim caps will be provided to participants in race packets and must be worn over the top of any other cap.  Swimmers will be responsible for marking their own caps on both sides with their assigned numbers in large, legible print (5 inches tall).  Nothing other than numbers may be written on caps. 


           Swim caps are numbered for identification and are also color coded, grouping participants by swimming pace to set the order for

           jumping from the ferry.  Color coded groups are based on a swimmer’s per mile pace in a pool, or the pace of the slowest swimmer a

           participant wishes to stay with during the race.  There will be three groups, designated as follows … 24 minutes or less per mile, 25-34

           minutes per mile, and 35-45 minutes per mile.  Once groups are assigned, there will be no changes to swim cap colors.

  • Timing Chip:  Timing chips will be provided to participants in the form of an anklet, enclosed in race packets.  Please make sure the anklet is returned to an event volunteer at the finish line.


5.  Self-Sufficient Feeding Requirement (from your buoy):  As it would be unsafe and logistically problematic for support boats to engage props to feed 400 swimmers in currents with water depths up to 300 feet where they cannot anchor, you are responsible for providing your own nutrition and carrying it with you during the swim (most likely in your swim buoy/dry bag).  Holding on to the buoy to feed is the only time a swimmer may legally hold on to anything for support without being disqualified. Obviously, it is encouraged for a distressed swimmer to hold on to their buoy if needed in an emergency requiring extraction, although once pulled from the water, the swimmer is disqualified.


Hint:  You will want to practice feeding in the open water with your buoy/dry bag.

6.  Gear Not Permitted


  • Propulsion, Breathing & Flotation Devices:  Propulsion devices (i.e. fins, paddles, webbed gloves, etc.) and breathing devices (i.e. snorkels) are not permitted.   No flotation devices are permitted other than required swim buoy/dry bag in tow (i.e. kick boards, pull buoys, etc.).  There will no longer be an “Aided” division.  


  • Audio Devices:  Swimmers may not use audio features on any electronic device or wear accessories for audio transmission from any electronic device.  Violation of this rule is a serious safety infraction.  Penalty is disqualification & extraction.  Swimmers must be able to hear boat motors and horns, sirens, directions being yelled to them with or without a bullhorn, etc.  While wearing ear plugs is not encouraged, but permitted for the comfort of the swimmer (i.e. prevention of ear infections), voluntarily inhibiting one's hearing for the sake of music is not permitted.  


7.  The Start:  The swim starts from the Star Line ferry Ottawa and requires a 5-6 foot jump to the water and an approximate 300-yard warm-up swim to shore.  Your official time does not begin until you cross the starting line mat on the beach at the southeast foot of the Mackinac Bridge, before re-entering the water.  Swimmers will have 15 minutes from the time the last swimmer jumps from the ferry to cross the starting line before being disqualified. 


Swimmers who miss the ferry’s departure from Star Line Dock #2, may start the swim from the Colonial Michilimackinac State Park beach, but will not qualify for overall or age-group awards (will only qualify for a finisher’s medal).  Swimmers starting from the beach must provide their own transportation and find parking.  Please note that Mighty Mac Swim vehicles left in the state park is not permitted after the Visitors Center opens at 8:00 a.m. 

8.  The Safety Fleet:  The U.S. Coast Guard (USCG) will establish and the law enforcement coalition will enforce a safety zone for the Mighty Mac Swim, protecting swimmers from boat traffic penetrating the swim course.  A 3-hour window free of commercial freighter traffic has been established from 7:30 – 10:30 a.m. 


A 500-passenger ferry will serve as our marine operational headquarters.  The ferry provides us the unique capability to pull up to all 400 swimmers from the water in emergency situations, provide medical oversight through an on-board EMS station, and evacuate the entire field of participants to shore in a single trip. 


We supply a fleet of power boats, motorized dinghies and personal watercraft in the open water of the Straits to lead and trail swimmers within the swim lane, guide swimmers from the swim lane perimeters and assist swimmers for their safety.  Among our support fleet is a dedicated EMS boat on constant patrol and on call.  In addition to the two EMS stations on the water, EMS personnel will be at the starting line, then move to a third EMS station at the finish line with a dedicated medical unit standing by.  All EMS station personnel are staffed by certified Paramedics and EMTs.  Certified lifeguards are assigned to the ferry, all support boats, shuttle dinghies and personal watercraft.


A fleet of kayaks will direct and assist swimmers in near-shore areas.

9.  No Dedicated Escorts:  The Mighty Mac Swim provides a fleet of support boats to help guide and safeguard all participants.  Swimmers will not be provided a dedicated support boat and are not allowed to provide their own personal escort (i.e. kayak). 



10.  Swimmer in Distress:  If you are in distress, in need of assistance or wish to exit the water for any reason, please hold on to your brightly colored buoy, blow your whistle and wave your arm over your head to get a support craft’s attention.  You will not sink, you will be seen and heard.


KNOW YOUR LIMITS.  Swimmers should get on a support craft whenever they feel their health or safety is in question.  Event staff including lifeguards, EMS professionals, watercraft crew, U.S. Coast Guard and the law enforcement coalition are all highly trained and will keep a diligent watch and utilize their specialized skills to help keep you safe.  However, there is no replacement for using common sense to make proper decisions. 


A swimmer may not re-enter the water once boarding a support craft, as they have been disqualified.

11.  Getting Your Attention (audio & visual signals):  Support craft will cautiously approach swimmers when taking some form of action and may audibly and visually signal warnings.  Boat horns are the most common audible signal used by our support boats, but law enforcement vessels may use sirens.  Bullhorns or a boat’s PA system may be used to communicate with swimmers.  Visually, support boat crew may wave one red flag when entering an area with swimmers, signaling CAUTION.  Two red flags notify swimmers to STOP AND APPROACH THE BOAT FOR INSTRUCTIONS.  The EMS boat and law enforcement vessels may use flashing lights.

12.  Disqualifications (related to safety)


The following disqualification standards are to protect not only the individual swimmer but are also to prevent scenarios which tax (spread out or divert) the safety fleet and affect the event’s ability to safeguard the swimming population.


  • Time Requirements for Race (see "7.  The Start" for Warm-Up Swim Time Requirement):   The cut-off time to complete the 4.15-mile race course is 4 hours from the official start time (when the last swimmer crosses the timing mat at the starting line).  A swimmer starting at the official start time, staying on course and keeping a pace of 57.83 per mile or faster will make all possible cut-off times at checkpoints on the course. 


            There are 5 possible checkpoints with cut-off times which may need to be met to stay in the race.  Checkpoints may or may not be

            monitored or enforced by race officials (utilizing a checkpoint may be dependent on whether lake conditions changed since the last


            The possible checkpoints, their distances from the starting line and their cut-off times (from official start time) are as follows:

            Possible Checkpoints & Cut-Off Times

            South Anchor Pier of Bridge:  1.04 miles from start - 1 hour cut-off

            South Bridge Tower:  1.49 miles from start - 1 hour, 26 minute cut-off

            North Bridge Tower:  2.21 miles from start - 2 hour, 8 minute cut-off

            North Anchor Pier of Bridge:  2.66 miles from start - 2 hour, 34 minute cut-off

            Beginning of Causeway:  3.38 miles from start - 3 hour, 15 minute cut-off


            See Checkpoint Maps Here (COMING SOON).


  • Staying on Course:  The swim will be conducted on the down current side of the bridge, and the ever changing direction and intensity of the cross currents will not be known until the morning of the swim (one of the idiosyncrasies of the Straits of Mackinac which make this swim truly unique … and your accomplishment when you succeed all of the more impressive). 


           Our fleet of support boats will form a perimeter 100 yards from either the east or west side of the bridge, thereby forming a swimming 

           lane for you, between the boats and the bridge.  Support craft will be stationed on and will patrol the outer perimeter, attempting to

           keep you on course.  If you are unable to stay within the 100-yard wide swim lane, you may unfortunately be disqualified and pulled

           from the water. 


           Sighting off the formation of support boats, which defines the outer perimeter of the swim lane when they are in their intended

           position, may be helpful to keep you on course.  However, please remember that these are “rescue boats” and will deviate from the

           perimeter if they need to assist a swimmer.  Perimeter boats will not always be on the perimeter.  The bridge however, will not move.

           As a word of advice, it is best to sight mostly off the bridge and try to swim as near to the bridge as possible (swimming right along the

           bridge pilings, rather than increasing the risk of drifting wayward and extraction by swimming near the outer perimeter).  It is no

           harder to swim straight in the currents next to the bridge than in the currents further away from it.  Plus, the further you get from the

           bridge, the harder it is to judge distance.  






















           If the currents are tough on game day, take heart in the fact that if you are able to battle and stay on course for the first 3.4 miles, the

           currents should no longer be a factor while swimming along the down-current side of the causeway and much of the home stretch to

           the finish line should be considerably easier!  Yes, the currents can be a challenge, but you have the mammoth, magnificent Mackinac

           Bridge to sight off and to get up close and personal with to stay on course! 


  • Discretionary Extractions:  A swimmer will be extracted anytime (if at the discretion of event authorities) a swimmer’s pace slows or their condition deteriorates to a degree which puts them or others in danger.

13.  Extraction, Transfer & Return to Shore:  Swimmers may be pulled from the water into

a support boat or dinghy, on to a personal watercraft or may self-board the ferry.  The

medical condition of extracted swimmers will be assessed.  Barring a medical emergency,

extracting crafts will transfer swimmers to the ferry where they will be held with medical

observation until the last swimmer is accounted for following the end of the race. 

Boarding the ferry will require ascending 5-6 feet up a ladder.  A tether and hoist may be

used for swimmers having difficulty boarding.  Lifeguards and other personnel will be

there to assist.  Swimmers in need of a hospital transport will be taken ashore to a waiting 

ambulance by the EMS Boat. 


Following a final head count reconciliation with the official timer at the finish line,

swimmers aboard the ferry will be returned to Star Line Ferry dock #2.  If applicable,

swimmers aboard support boats will be taken to the St. Ignace Marina.  Shuttle service to

the Bridge View Park finish line or to parked vehicles will be provided for swimmers

without vehicles parked in the vicinity or without arrangements for pick-up.



 14.  Safety Decisions Are Final:  All decisions made by event officials, emergency medical professionals, lifeguards, the U.S Coast Guard, all law enforcement entities or anyone acting under the direction of the aforementioned is FINAL.  The USCG Patrol Command has the utmost authority to make event decisions related to safety and is part of the marine operational headquarters team aboard the ferry (with event officials).

15.  Refunds & Transfers:  Entry fees are not outright refundable and may not be deferred to the following year.  Once the event is sold out, an entry may be transferred to the first agreeable person on the waiting list (starting at the top of the list) and the entry fee thereby refunded, up until June 30th.  While a transfer to the waiting list will be attempted, a transfer cannot be guaranteed.  There will be no transfers after June 30th.



 16.  Delays & Cancellation:  While every attempt will be made to hold the event as planned, the race may be delayed or cancelled at the discretion of event officials and/or the U.S. Coast Guard patrol command without refunds given to participants for circumstances beyond the control of event organizers.  These circumstances include, but are not limited to, adverse weather and lake conditions on the day of the race which threaten the safety of participants and support crews.  The start of the race can be delayed until 8:15 a.m. before being cancelled (approximately 1 hour, 15 minutes from the approximate start time), due to the expiration of the 3-hour window free of commercial freighter traffic in the shipping lane at 10:30 a.m.  Unfortunately, a cancelled race cannot be rescheduled.   

You Will Also Want to Know the Following Before the Swim


17.  Protection for Your Feet:  The lake bottom is extremely rocky, at both the start and finish, so neoprene socks are highly recommended.  Surf shoes add even more protection if you don’t mind swimming with them and taking time to store them in your buoy/dry bag.  It is advantageous to stay in the swimming position as far into shallow water as possible before standing and wading ashore.

18.  RaceJoy for Tracking Your Position:  If someone loves you they may want to keep track of you while you’re swimming and will also likely be concerned about your condition if you are pulled from the water.   The event would also like to have the capability to track you in the water.


Mighty Mac Swim participants carrying their cell phone in their swim buoy/dry bag can be tracked by family & friends, as well as by the safety fleet, on the RaceJoy mobile tracking application.  Swimmers just need to download the RaceJoy application on to their phone, follow the directions to set up their profile and choose to be tracked in the Mighty Mac Swim.


We will have an Information Station (tent) at the finish line where information on swimmers pulled from the water will be displayed.  The names of extracted swimmers will scroll on a display screen, confirming they are okay and safely being held on the ferry with medical observation for the remainder of the race, before being returned to the Star Line Ferry dock #2 in St. Ignace.  If an extracted swimmer is being transported to shore for medical reasons, a notation on the screen will ask family to “please inquire.”  Information Station personnel will notify the swimmer’s emergency contact and hospital information will be provided.

19.  Competition Rule Violations & Penalties:  Lifeguards are Course Monitors


  • Drafting:  A swimmer observed following closely behind a support craft, drafting in their wake, will be warned once and disqualified if incurring a second infraction.  Drafting behind other swimmers will not be monitored.  Swimmers are asked to try to avoid making contact with other participants.  


  • Holding on to an Object for Support:  Swimmers observed holding on to a support craft or any other object for support will be disqualified.  While swimmers may hold on to their buoy/dry bag when feeding, holding on to a buoy while making forward progress or to rest (in a course monitor's judgement) are infractions subject to disqualification.  Swimmers SHOULD hold on to their buoy and signal distress in an emergency.  


  • Boarding a Support Craft:   A swimmer who has exited the water, including the voluntary or involuntary boarding of a support craft, has been disqualified and may not re-enter the water.   





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