Is Sandy Hook Light on the Move?

I had been warned about the swirling currents of Hell Gate, but it was the profusion of lights from ships, shore and navigational aids that overwhelmed me as I entered Lower New York Bay after sunset in search of an overnight anchorage.
Author:
Updated:
Original:
Sandy-Hook-Lighthouse

I had been warned about the swirling currents of Hell Gate, but it was the profusion of lights from ships, shore and navigational aids that overwhelmed me as I entered Lower New York Bay after sunset in search of an overnight anchorage. Most of the harbor is wide open to the wind and swells coming in from the Atlantic, but Sandy Hook, a narrow point of land that extends north into the harbor, offers sufficient protection for the southeast corner of the bay. I turned my bow south and looked for the Sandy Hook lighthouse.

Set against the surrounding Jersey Shore, Sandy Hook is an oddity. It is a long and narrow barrier spit, nearly six miles long and one mile wide. I looked at the chart and wondered why the lighthouse was in the middle of the spit and not on the end.

As it turns out, when it was first built in 1764, the Sandy Hook lighthouse actually was on the northern end of the spit. However, as the sand around it shifted over time due to longshore drift, the lighthouse moved miles inland. 

Longshore drift is a current that travels parallel to the shoreline. At Sandy Hook, it carries sand from the inland end of the spit and deposits it on the shore, extending the spit long past where the lighthouse stands. 

Only two things need to be present to create the energy that drives the current: waves and gravity. The wind generates waves, which approach the shore and are pushed up the beach at the angle of wind direction. When the waves retreat, gravity pulls the water straight down the beach slope. The waves approach and retreat at differing angles, creating a net flow sideways along the shore. Erosion from the waves traps sand in the current and moves it along with the water until the current reaches the end of the land and loses energy. Any sand particles that were suspended in the water are deposited there. 

That is how Sandy Point came to be. After some time, the barrier spit was long enough to become a navigational concern for ships, so a lighthouse was built near the end of it. Then as the years passed, longshore drift continued to carry sand along the shore and deposit it at the end of the spit, extending it 1.5 miles farther into the bay.

Illustration by Ben Eriksen

Related

Beneyteau-Excess12

Boat Review: Excess 12

Groupe Beneteau, builder of Lagoon catamarans, has introduced a new multihull line called Excess. The first of the boats to reach U.S. shores at the Annapolis boat show was the Excess 12, a 38ft 6in design based on the popular Lagoon 40. The thought process behind this new boat ...read more

Spindriftracing

Extreme Sailing: No Piece of Cake

It can be easy to take for granted the incredible performance of today’s most cutting-edge grand prix racing boats. The latest crop of full-foiling 75ft America’s Cup monohulls, for example, were all up on their foils and even successfully tacking within hours of their first ...read more

Solar-Dinghy-pump-photo

Gear: Solar Powered Dinghy Pump

Tired of forever finding your dinghy or open daysailer filled with water when you arrive to go sailing? For years, sailors and engineers have sought a solution to this seemingly eternal problem, and now it appears the folks at Sea Joule Marine may have finally found it in their ...read more

BestBoatPromo-03

Best Boats 2020

How’s this for a thought experiment: imagine setting a diminutive Tiwal 2 inflatable dinghy alongside a Catalina 545 cruiser? It would be hard to imagine two more different watercraft, and yet they are both still very much sailboats. They are also both winners in this year’s ...read more

Hanse-675

Video Tour: Hanse 675

This past fall at the Annapolis Sailboat show, we had a chance to catch up with Hanse’s  Maxim Neumann, who kindly provided us a tour of the company’s new flagship, the Hanse 675. An impressive, well-built production yacht that boldly ventures into maxi-yacht territory, the ...read more

TOTW_PromoSite

SAIL's Tip of the Week

Presented by Vetus-Maxwell. Got a tip? Send it to sailmail@sailmagazine.com Be thrifty with propane  If you like to cook on board, the propane tanks supplied as standard with many modern yachts won’t get you far. Whether we bake bread or not, the one thing we all do is boil ...read more