The islands are used for several different types of recreational activities, including camping, boating, kayaking, swimming, bird watching.

Ownership of the islands varies, with about a half dozen held in private hands, some owned by the governments of Norwalk or Westport and some are part of the Stewart B. McKinney National Wildlife Refuge.

[1] Geologists generally consider the islands to be terminal moraines—material left by glaciers—deposited about 17,500 years ago as the ice cap paused in its retreat northward.

Tidal currents are gentle, the mainland is always visible and the electric power plant on Manresa Island helps with navigation[1] (although if fog hits it can cause sudden and complete disorientation[2]).

[1] Striped bass, bluefish, fluke, flounder, false albacore, bonito, trout, and dogfish can be caught off the islands.

The Marine Mammal Protection Act prohibits harassing the animals and sets limits on how close observers may get.

[2] Flora include thorn thickets, wild blackberries, black cherry, bittersweet, sassafras, juniper and honeysuckle.

[1][2] Sheffield Island, according to the planning agency brochure, has a "considerable nesting potential" for osprey, herons and other migratory species.

[2] At 59 acres (24 ha) Chimon is the largest of the islands and is located in the middle of the group and a bit less than a mile to the southeast of the entrance to Norwalk Harbor.

Owned by the Westport town government, the island (Pronounced "koh-KEE-nee" or "kuh-KEE-nee") has almost all the bird rookeries in the chain.

The cormorants' guano, which leaves some of the rocks white, is toxic to the trees and kills them off after the birds nest in a spot for less than a year.

[4] Once called "Ram Island", the 45 acres (18 ha)[2] isle was renamed after Daniel Shea, a Congressional Medal of Honor recipient from Norwalk who died in the Vietnam War.

[1] Along with Grassy Island, Shea is open to the public from May through Columbus Day, and campers with a permit can stay overnight.