Shamrock CPO - Canton Flannel

A modern expression of maritime tradition, the Shamrock Flannel Overshirt bridges rugged heritage and refined comfort. Woven from our heavyweight Canton Flannel, it offers a softer, more laid-back take on the classic CPO—designed for crisp fall mornings, long sails, and evenings by the fire. Each piece is crafted in Massachusetts, continuing over eight decades of American manufacturing excellence that began in the shipyards and harbors of New England. The fabric’s brushed finish delivers a rich hand feel, while its durable weave ensures it stands up to seasons of wear, developing character with time. Every element of the Shamrock has been considered through the lens of purpose and tradition—from the angled buttonholes designed for ease of use to the custom Nut Ivory buttons, engraved with our signature buoy. A traditional locker loop and tailored cuffs nod to its naval roots, while the flannel’s natural warmth brings a new dimension of versatility to the collection. Whether layered ove