Thacher Island

Thacher Island gets its name from one of the earliest and still more poignant shipwrecks on the Massachusetts coast.


Thacher Island gets its name from one of the earliest and still more poignant shipwrecks on the Massachusetts coast. In August of 1635 two young families sailed from Ipswich in a small pinnace bound for Marblehead, just over 25 miles away. John Avery was the newly appointed pastor in that already notorious town — “because many there (the most being fishermen) were something remiss in their behavior.” Avery’s cousin Anthony Thacher was aboard, along with the two men’s wives, their ten children, and other relatives, passengers, and four mariners, for a total of twenty-three.

According to Thacher’s account in a letter to his brother in London, two days into the voyage (!) the pinnace’s old sails blew out, and the sailors anchored for the night.

But before light it pleased the Lord to send so mighty a storm as the like was never known in New England since the English came, nor in the memory of the Indians.
It was so furious that our anchors came home. Whereupon the mariners let out more cable which at last slipped away. Then our sailors knew not what to do, but we were driven before wind and waves.

The pinnace fetched up on a small rocky island just east of Cape Ann, where:

The waves came furiously and violently over us and against us. . . but beat her all to pieces. Now. . . consider my misery who beheld the ship broken. . . my goods and provisions swimming in the seas, my friends almost drowned, and mine own poor children. . . before mine eyes drown and ready to be swallowed up and dashed to pieces against the rocks by the merciless waves, and myself ready to accompany them.
{all quotations ECP pp.6-7}

In the event, Thacher and his wife Elizabeth washed ashore and survived. All ten children from the two families were drowned, along with the other adults, and the sailors.

Afterwards, with an act of almost cruelly ironic generosity, the Massachusetts General Court gave to the Thachers the title to the island which still bears their name.


📷 Geoff Rand
The identical north and south towers on Thacher Island are the last remaining example of twin lights on the Atlantic coast. Once an important method of distinguishing between nearby locations, twin lights became obsolete as rotating, timed flashes served the purpose more efficiently. In fact, when the current lights on Thacher were built to replace deteriorating twins in the 1860s, the justification for a second tower was described as “entirely sentimental” and ascribed to “Cape Ann conservatism.” {ECP, p.97}
“. . . this island and its twin lights are the keys to Boston Harbor.”

This observation by an agent of the Portland Steam Packet Company in 1853 {ECP, p.48} must have been at least half true throughout the great ages of both sail and steam navigation. Boston-bound vessels from the Gulf of Maine, the Canadian Maritimes, and northern Europe would all pass close by Cape Ann. Just as the lights at Minots and Little Brewster guided mariners into Boston from the south, the lights on Thacher did the same from the north, as they still do today.

Not for navigation


Arriving from the south, you can cross the bar between Milk and Thacher Islands with about 10 feet at low. Run a course to or from the nun on Oak Rock to keep in the deepest water.

The jumble of ledges north of the island and outside Sandy Bay are mostly visible and well enough marked for clear weather but can be tricky to navigate in the dark or fog.

East of Thacher is the low-lying “Londoner”, marked by a not-very-distinctive pole. The rocks are covered at most tides and break only slightly in fair weather, but there is plenty of deep water to pass between the island and the ledge.

📷 Geoff Rand
The north tower sits on land that is now a National Wildlife Sanctuary. The light was decommissioned in the 1930s; today it shows a privately maintained fixed yellow light.
📷 Geoff Rand
This pole sits on the Londoner, a ledge just east of Thacher Island. Most first-time navigators to the area have trouble identifying the beacon on the water and finding it on the chart.


The obvious spot to anchor, just west of the boat ramp in the middle of the island, is off limits; it’s a cable area that’s been in use for over a hundred years. Otherwise, the water around Thacher is either deep, steep, and rocky or completely exposed. This is not a place you’ll feel comfortable anchoring and leaving the boat.


There are a couple moorings for visitors just off the boat ramp with at least 10 feet of water at low. The island’s keepers request that you call ahead before picking one up to be sure it’s available

The moorings are a great convenience for a short island visit, but they are too exposed for an overnight stay.


Not for navigation. Charts are not updated. 

Going Ashore

The northern part of Thacher is a Federal Wildlife Sanctuary and the southern part is owned by the Town of Rockport. In the center, near the south tower, is the (private) caretaker’s cottage with an adjacent small but nicely executed museum focused on island and lighthouse history. There are also a handful of reservable campsites. A system of trails emanating from the boat ramp provides access to most of the island.

Thacher is home to a good-sized seagull population. During their nesting season from May through July they are very aggressive defending their eggs and their fledgling, still-flightless chicks. As you get much away from the center of the island the gulls get denser and the trails less hospitable — especially when there is a gull chick hopping along the trail ahead of you

📷 Geoff Rand
Pulling a kayak up the boat ramp.
📷 Geoff Rand
A narrow railroad and wooden path helped move supplies from the boat ramp to the buildings inland.

One Hour Ashore

An hour is about right to tour the island.

Off the Beaten Path

Most evidence of current and prior human activity on Thacher is concentrated in the triangle bounded by the north tower, the south tower, and the boat ramp. Follow trails off to the southwest corner of the island to reach an area that’s been allowed to grow in more “naturally”. But be prepared — the gulls are if possible even more vociferous down here.

Maritime History

The original twin lights were first lit in 1771, under direction of the Massachusetts Bay Colony. Cape Ann Light Station was, depending on how you count, the tenth or eleventh or twelfth light in what is now the United States, and the last established in the colonial era.

Rainy Day

Visiting Thacher in the fog and rain of a northeaster would give you a heightened sense of its historic role. But the little museum can only offer fifteen minutes or so of indoor distraction.



Land your dinghy on the boat ramp, then pull it up the ramp and off to the side. Groups of kayaks frequently paddle to the island from Rockport, and a custom landing boat makes regular visits as well, so the ramp must be kept clear.

There is a restroom off the museum’s gallery and a privy near the campsites.

Fitting Out

There are no supplies or services on the island.


Island Keeper

Thacher Island Association
TIA is a non-profit dedicated to the preservation and upkeep of the island.





If you have updated information, corrections, or contributions to this harbor, please share them below. Comments are moderated by Boston Sailing Center. 

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Therese Sellers
Therese Sellers
1 year ago

Thank you for this detailed and fascinating guide to Thacher Island! I especially appreciate the history, navigational information and beautiful photos. We very much hope to visit by sail.

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