To reach the trail, park at the trailhead marked for the Kabeyun Trail, accessible from ON-587. Follow that trail until about the half-mile mark, when the Sea Lion Trail branches off. Don't worry about missing it; signs are posted around the junction.
The trail is rockier and steeper than the Kabeyun Trail, though nothing very strenuous. Soon, you'll reach its end, a fenced overlook of the arch. Be vigilant of steep cliffs if you choose to venture around the fence for a better view.