Maine's Acadia & Bar Harbor Region have spectacularly beautiful beaches

Sand Beach in on the east side of the island within Acadia National Park. It is in a gorgeous setting between two large walls of granite and evergreen. The 300-yard beach is composed of sand from shell fragments. The ocean water is a cool 55 degrees F even in summer. Sand Beach is staffed with lifeguards during the summer. Beach is off-limits to pets from June 15 to September 8.
Sand Beach is reached via the Park Loop Road; you will need to have a park entrance pass. It is 5 to 6 miles from downtown Bar Harbor. All about park fees and entrance passes.

The Free Island Explorer Shuttle Bus Service makes regular stops (in season) at Bar Harbor beaches. View the #3 Sand Beach/Blackwoods Route and the #4 Loop Road Route for Sand Beach.

Shackford Head State Park covers 90 acres on Moose Island overlooking Cobscook Bay. This undeveloped park on a peninsula has beaches, coves, and a dramatic headland at Shackford Head. Several miles of trails cross the headland. An easy hike of one mile from the parking area through the woods to the rocky headland allows beautiful views of Cobscook Bay. No admission fee. - Trail Map (PDF)

This ocean beach is in the center of town on the southeastern side of Mount Desert Island. This is a quaint little beach with great views of expensive yachts immediately off shore. The beach is right next to Route 3 and across the street from the Acadia National Park Stanley Brook entrance.
One way to get to Seal Harbor is via Route 3 heading south from Bar Harbor. Another is the Park Loop Road. There is a turn-off south of Jordan Pond. Acadia National Park land surrounds the village. The Free Island Explorer Shuttle Bus Service makes regular stops (in season) at Bar Harbor beaches. View the #5 Jordan Pond Route for Seal Harbor Beach