More than 2,000 navigational beacons, big and small, oversee the nation’s 60,000-mile-long coast. Now they need an upgrade.

The 3rd order Fresnel lens in the Au Sable Light Station appears to glow orange in as it refracts the light from the sunrise near Grand Marais, Mich., in Pictured Rocks National Lakeshore.

The Fresnel lens was made by Sautter & Lemonnier of Paris, France. When it was operational, the light produced a focal plane 58 feet above the mean low water level of the lake.

NEWBURYPORT — Like a long-awaited Christmas present, volunteers and staff at the Custom House Maritime Museum spent some of Thursday morning carefully unwrapping a $400,000 Fresnel lens once used to ...

The Fresnel lens was made by Sautter & Lemonnier of Paris, France. When it was operational, the light produced a focal plane 58 feet above the mean low water level of the lake.