Changing Shape of the Cape & Islands: Chatham’s Monomoy Islands and Stage Harbor

Monomoy Point Lighthouse (6). Though at one time the light stood just 180 feet from the beach, as a result of sand accretion over the years the light is a considerable distance inland today. Photograph by Josh Shortsleeve (2016)

According to Stuart Smith, Chatham’s harbormaster, this breach has also caused more trouble for Stage Harbor (8). “It created additional sand movement,” Smith says. “The sand is moved west through the breach toward the channel and is being dumped into the harbor.” During the past 15 years, Smith says, Stage Harbor has been dredged a few times, adding that another round is overdue. “Boaters that use the channel are generally aware [of the increased sediment],” Smith says. “It’s not like it’s a surprise—what’s surprising is the rate at which it’s shoaling. It continues to be a challenge.”

The changes Monomoy has weathered over the years will continue to occur, Keon says. Having stretched all the way to South Monomoy (2), South Beach (3), Keon says, has thinned out and may be vulnerable to future breaches. “South Beach is eating itself,” he says. “It’s breaking apart as sediment continues being carried south. It’s eroding on the east shore while gaining on the west.” Eventually, the pileup could bring Monomoy and Morris Island back together.

For boaters who wish to explore the waters around Chatham and Monomoy, Smith offers some advice. “Follow the buoys and pay attention to the tides,” he says. “The breaking surf on the shoals can cause trouble. Chatham continues to be a difficult place to navigate, but it’s such a beautiful, pristine place.”

Christopher Setterlund is a freelance writer from South Yarmouth.