Paddling under the Mackinac bridge and through the Straits of Mackinac in general can present several dangers. Currents in the straits can be very treacherous!
Do not attempt this without an appropriate sea kayak, proper safety equipment, and training!
A few years ago, on our return from the Great Lakes Sea Kayak Symposium and a side trip paddling Lake Huron's Les Cheneaux Islands, we stayed at the Straits State Park. The park is located on the St. Ignace side or northern shore of the Mackinac Straits. It’s only a few hundred yards away from the “Mighty Mac”, otherwise known as the Mackinac Bridge.
From the state park campground you can launch your kayak easily. The beach is a combination of sand and gravel. The state park is an ideal location to explore the St. Ignace and Mackinac Island area from.
Kayaking Under the Mackinac Bridge
We set off in the late afternoon and paddled along the bridge’s ramparts. These extend out about a little more than a half mile before the bridge is elevated over the water. A few hundred yards from shore there is a small passage under the bridge that permits small boats to pass under the bridge without having to venture out the straits themselves. We paddled through this for our first paddle under bridge. Not exciting but it did allow us to see what the wind conditions were like on the Lake Michigan side of the bridge.
During this time we had our VHF marine radio on and were listening for ship traffic. We also kept a look out for any freighter that might be passing under the bridge as we prepared to paddle out the span where boat traffic and freighters pass under the bridge. It is important to realize that passing freighters can kick up a large wake and waves in the six to eight-foot range are common. It is best to time your crossing to avoid freighters and their wakes.
We then paddled southward parallel to the bridge until we arrived at the first suspension tower. At this point we paddled under the bridge from the Lake Michigan side to the Lake Huron side. The view of the underside of the bridge and the sound of traffic above was surprising as it much higher than we had realized, and the sounds were much quieter than we expected.
The current and waves under the bridge were challenging. It wasn’t so much the size of the waves, we’ve paddled in waves of this size before, but rather that the waves were disorganized. Waves on the Great lakes are caused by wind. Normally they follow a pattern one can adjust or accommodate for this. Under and near the bridge however, the waves were random and unsettled. Add in a bit of current and the conditions were all together unique to us. Once we made it clear of the bridge, the conditions settled down.
After passing under the Mackinac bridge, we set a course toward St. Ignace. The Lake Huron side was calmer, and the waves diminished as we approached St. Ignace. We spent some time exploring the area near town before we returned to the state park campground. We arrived back on shore as the daylight faded.
Will we paddle under the bridge again? Probably not. The risk/reward ratio doesn’t really make sense. We had been drawn to the iconic landmark and as much as it was intriguing and interesting, frankly we’d rather seek out more scenic or wild areas to paddle.
The current is prone to change directions and combined with wind-blown waves, and waves from passing freighters, along with rebound off of the bridge pilings, paddling a kayak under the bridge can be challenging and should not be done unless you are a skilled paddler and can perform a self-rescue in rough conditions.
For an in depth study about the current flow through the straits, see this article by James Saylor and Gerald Miller of the Great Lakes Environmental Research Laboratory Ann Arbor, Michigan