Is Sandy Hook Light on the Move? - Sail Magazine

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:
Publish date:
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

daviscards

Davis Instruments: Quick Reference Cards

CHECK THESEIf you’re sailing with new crew this summer or your kids have suddenly and inexplicably started to look up from their phones and take an interest in the finer points of cruising, these Quick Reference Cards from Davis are a great way to further their boating education. ...read more

01-rbir18-596

Another Epic Round Britain Race

There are basically two kinds of offshore sailboat races out there: those that take place annually, like the Fastnet and Chicago-to-Mackinac races; and those that take place every other year, like the Transpac and Newport-Bermuda race, in part so the competitors have sufficient ...read more

01b_WALKING-KEDGE-OUT-cmykpromo

Getting More Use From Kedge Anchors

If you are cruising, you need at least two anchors on board for the simple reason that you must have a backup. Imagine having to slip your anchor on a stormy night with other boats dragging down on yours, or having your rope rode severed by some unseen underwater obstacle, ...read more

SailAwayCharter

How-to: Navigating on a Bareboat Charter

So you graduated from navigation class where you practiced dead reckoning, doubling the angle on the bow and maybe even celestial nav, and you now feel well prepared for your first charter trip. Well, you won’t be doing any of that on vacation—not past the first day, anyway.Most ...read more

04-Turtle-rescue

Turtle Rescue in the Vic-Maui

Strange and often wonderful things can happen in the course of an offshore sailboat race, and one of the strangest and most wonderful things we’ve heard of recently took place during the 2,300-mile 2018 Vic-Maui race, from Victoria, British Columbia, to Lahaina, Hawaii.It ...read more

dorcap-open-blue

ATN Inc: Dorcap

COOL SLEEPYou’re fast asleep in a snug anchorage, forehatch open to catch the breeze, when you’re rudely awakened by a sneaky rain squall. Now you’re not only awake and wet, you’re sweltering with the hatch closed. Sucks, right? That’s why ATN came up with the Dorcap, an ...read more

HIGH-RES-29312-Tahiti-GSP

Ask Sail: Who has the right-of-way

WHO HAS RIGHT-OF-WAY?Q: I sail in Narragansett Bay, which is a relatively narrow body of water that has upwind boats generally going south and downwind boats generally going north. When sailboats are racing, the starboard tack boat has the right-of-way over the port tack boat, so ...read more