SwimRun Casco Bay 2026

The SwimRun Casco Bay is where the history of American SwimRun took its first big plunge—and you’re going to come write the next chapter on Great Diamond Island (Casco Bay, Maine) 🌊.

Expect sea crossings that wake you up, tides that change the vibe from one leg to the next, coastal terrain sections where you play with your footing, and bits of history that pop up around the bend 🪨.

You choose your adventure: Casco Bay Sprint to discover without burning yourself out, Casco Bay Experience for a true “best-of” of the islands, or the Casco Bay World Series to taste the legendary version—the one that makes you say, “okay, that’s why I came” 🏁.

After the finish line, stick around: take a detour to Fort McKinley on Great Diamond Island, then hop on the ferry to go stroll around Portland (Old Port and its wharves), or push on to Portland Head Light in Cape Elizabeth for the coastal classic.

If you’re coming as a duo or with family, plan an end of day on Peaks Island (bike rental, little beaches), or a simple sunset stroll along the shore of Great Diamond Island: salt on your skin, a smile on your face, and the feeling you’ve had your best day.