Bill Dunn, a volunteer trustee of the Sea Girt Lighthouse, explains how the beacon in the tower room helped mariners traveling along the New Jersey coastline navigate a safe passage to their destination. ERIC SUCAR staff I magine being a mariner traveling on a ship on the Atlantic Ocean along the coast of New Jersey at night. It’s pitch black. There are no homes and businesses lighting up the shore because it’s Dec. 10, 1896, and electric lighting isn’t widely available. What do you do? How do you find your way as the waves toss your vessel about?

Then you see it: a beacon of light in the distance, and now you know you are on the right path to civilization. You check your charts and, according to the sequence of blinking lights, you know it’s the new Sea Girt Lighthouse, illuminated for the first time that very day, and it means you are approaching the Sea Girt Inlet (today that inlet, which has since shoaled up, is called Wreck Pond).

Visitors to the Sea Girt Lighthouse can see a replica of the weight that helped turn the beacon. The Sea Girt Lighthouse was constructed to illuminate a blind spot that mariners encountered as they sailed out of range of the Twin Lights beacons in Atlantic Highlands to the north and Barnegat Lighthouse (Old Barney) to the south. Shipping firms and mariners lobbied for a light that was midway between those two sentinels because as many as 90 ships are said to have foundered off the North Jersey coast during the 1880s and 1890s.

Imagine being a lighthouse keeper in the lighthouse that day. Then you would be Maj. Abraham G. Wolf, a Civil War veteran who served in the Union Army. As Sea Girt Lighthouse’s first keeper, he was paid $1.10 per day, and his life, and the lives of those who followed, revolved around making sure the light continued to shine through the night, and cleaning it during the day, as the lighthouses projected beacons from sunset to sunrise.

Lighthouse keepers and their families had to make sure the beacon continued to shine, no matter what happened in their lives. If the keeper died, his wife and family were bound to keep the light shining while they grieved, as was the case for Harriet Yates, who kept it going for two months.

Those who visit the lighthouse will hear many interesting stories of the keepers and their families, including one who was a spy and another whose background was a mystery until recently.

But how did the light shine 13 miles out to sea without electricity? It’s one of Bill Dunn’s favorite stories to tell children who take the tour of the Sea Girt Lighthouse, which still stands at the corner of Ocean Avenue and Beacon Boulevard, across from the Sea Girt boardwalk’s northernmost point.

Dunn, a lifelong resident of Sea Girt, visited the lighthouse throughout his childhood and is one of the trustees of the Sea Girt Lighthouse Citizens Committee, which rescued the aging lighthouse from being torn down after falling into disrepair in 1980, and raised funds to have the building renovated.

The committee now leases the building from the municipality of Sea Girt for $1 per year. Many members, like Dunn, care for the building (which is now used as a meeting place by many local groups). They also conduct tours on Sundays from 2 to 4 p.m. from April through November, except on holiday weekends, to keep the spirit and history of the lighthouse shining.

Dunn says that when he tells the story of how the lighthouse keeper had to walk through the building by candlelight and climb up to the tower to light the flame that illuminated the beacon, a child on the tour often asks why the lighthouse keeper didn’t just flip on the light switch, to the amusement of the adults on the tour.

Dunn patiently takes that child, along with all others who visit the Sea Girt Lighthouse, through a history lesson, the likes of which they will never forget — especially when they get to climb up a ladder in the tower into the lantern room and behold the majesticAtlantic, its shores and the surrounding town as it looks now, and imagine what it was like in the past.

Visitors to the Sea Girt Lighthouse will learn about how lighthouses work and how lighthouses along the coast were designed, using local material, each with its own distinct appearance, so that mariners could use the buildings as landmarks during daylight travel.

The Sea Girt Lighthouse is a red brick building that resembles a house with a tower. This lighthouse was considered to be a very fine dwelling back in the day, because it served as the keeper’s office as well as living quarters, complete with the convenience of hot and cold water, a bath and heat supplied by six coal fireplaces.

You may be wondering how the lights could flash on a building that did not have electricity until the 1920s. If you visit the Sea Girt Lighthouse, you will see a Fresnel lens, much like the original one that lit the way to safety for so many sea captains.

The beehive-shaped Fresnel lens had four curved sides with bull’seye prisms on two adjoining sides. The other sides had brass doors to access the interior. A red light was produced by a kerosene wick lamp. The illusion of blinking was created by the rotation of the Fresnel lens.

The light projected through the bull’s eyes, followed by darkness as the doors swung around to block projection, then lit once more as the bull’s eyes came around again. A weight dropped down a tower shaft into the keeper’s office on the first floor. The weight drove gears that caused the lens to revolve. The descent took 7.5 hours. Agong would chime when the weight got to the bottom, signaling the keeper to climb to the tower and crank the weight back up. In 1912, an oil vapor lamp replaced the kerosene lamp and to create a brighter, white light, the chimney inside the lens was changed from red to clear glass. In 1924, an electric 300-watt lamp replaced the oil lamp.

A visit to the Sea Girt Lighthouse will shine a light on many historic events and organizations. Visitors will find out about how the Coast Guard was given the authority to run the lighthouses by President Roosevelt in 1939; how all beacons were extinguished during World War II to protect the coast from invaders; and about wrecks and rescues at sea, such as the Morro Castle in which 137 people perished on Sept. 8, 1934. Photos of the wreckage on the shores of Asbury Park are on display at the lighthouse.

When you enter the Sea Girt Lighthouse, you will get to touch the original banisters leading up to the second level, as well as original wooden shutters and moldings, fireplaces and some furniture that was actually used by the former keepers.

Period furniture, historic photos, maps and other artifacts such as spyglasses used by mariners, present the Sea Girt Lighthouse story. The always-expanding exhibits include photos and documents of the light keepers and a replica of the weight that turned the tower lens.

If you go, don’t forget to ask about the Bravest Woman in America, and be sure to look for photos of the lifeguards who used bicycles to patrol the beaches of Sea Girt up until the 1930s.

The Sea Girt Lighthouse is a stop on the annual Lighthouse Challenge of New Jersey, slated for Oct. 20-21 (www.lighthousechallengenj.org).

For more information, visit www.seagirtlighthouse.com or call 732-974-0514.