Lights Against the Sea: North America's Atlantic Coast Shipwrecks and Lighthouses, 1715–2026

A Light Beside Every Port

On 14 September 1716 the keeper George Worthylake lit the candles of Boston Light on Little Brewster Island, and for almost twenty years it was the only lighthouse on a coast that runs from the Florida Keys to Greenland. By 1900 there were more than 320 lighthouses and lightships, and set against the 7,200 recorded wrecks on this map they give a surprising answer: in Ireland a new light meant about 18% fewer wrecks nearby, in the North Sea about 12%, and here, taken as a whole, nothing at all.

The average hides two coasts. Near lightships and Canada's lights the wrecks did fall. Near US lighthouses they did not, because so many went up beside harbours whose traffic grew faster than any light could tame. Watch New York in the animation: the sea off Sandy Hook turns from orange to red in the 1850s, and from 1900 to 1920 it is the only magenta patch on the whole map, while one light after another is lit around it.

Treasure, Pirates and a Single Light

The map opens on 31 July 1715, when a hurricane drove eleven ships of the Spanish treasure fleet, carrying the silver of two fleets home from Havana, onto the reefs of Florida's east coast. About 1,000 people died, and divers are still raising its gold and silver along what is now called the Treasure Coast. In April 1717 Black Sam Bellamy's pirate flagship Whydah broke up in a nor'easter off Cape Cod and only two of her crew reached the beach alive. Her wreck, found in 1984, was the first pirate wreck ever identified beyond doubt, by a bell raised in 1985 that carries her name.

The French lit the first lighthouse in what is now Canada at Louisbourg in 1734, and Sambro Island at the mouth of Halifax Harbour, paid for by a tax on incoming ships in the very first act of Nova Scotia's new House of Assembly, was lit in 1759; it is the oldest working lighthouse in the Americas. In 1775 the whole coast still had eleven lights, and the worst disasters of the century were storms no light could have helped with. That September a hurricane fell on Newfoundland's fishing coast and killed at least 4,000 people, most of them fishermen; in 1782 a British convoy under Admiral Thomas Graves, bringing French prizes home from Jamaica, met a hurricane off the Grand Banks and lost some 3,500 sailors. The new US Congress took over the country's lighthouses in 1789, in only its ninth act.

Graveyards of the Atlantic

As the record fills up in the 19th century, the same places keep lighting up: the approaches to New York, where so many ships came ashore near Manasquan that the records simply call the stretch 'Squan Beach'; Cape Hatteras and the Outer Banks, the 'Graveyard of the Atlantic', with an estimated 2,000 ships lost; Charleston, where blockade runners piled up during the Civil War; Cape Cod and Nantucket; and in Canada Cape Sable Island, the Bay of Fundy, the Magdalen Islands, the Grand Banks and Sable Island, a sandbar in the open Atlantic with about 350 recorded wrecks between 1583 and 1947. The worst shoal was hard to mark at all: Diamond Shoals off Hatteras got a lightship in 1824, lost it in 1827, when it was wrecked near Ocracoke Inlet, and had none again until the 1890s.

Saving the people came long before saving the ships. In 1848, after Congressman William Newell reported that 158 sailing vessels had been lost on the New Jersey shore in ten years, Congress voted $10,000 for surfboats, rockets and boathouses, the first federal money for saving shipwrecked people. After the navy gunboat Huron went aground off Nags Head in November 1877, a week before the local station was manned for the season, and 98 men drowned, the Life-Saving Service became a separate bureau. From 1871 to 1914 its surfmen, on all American coasts, went to the aid of 28,121 vessels and 178,741 people, and 1,455 lives were lost. The ships still went aground; far fewer of the people on them died.

Disasters and the Lights They Built

Some lights were a direct answer to a disaster. In February 1860 the Allan Line steamer Hungarian struck Cape Ledge off Cape Sable Island at night and broke up with all 205 aboard; the wreck finally moved the government to act on years of petitions, and the first Cape Sable lighthouse was lit in November 1861. More often the answer was a rule or a machine: steamer lanes across the North Atlantic, proposed by Matthew Fontaine Maury after the Collins liner Arctic sank off Newfoundland in 1854 with no woman or child among the survivors, and the world's first steam fog alarm, installed by Robert Foulis on Partridge Island in the Bay of Fundy in 1859, where fog, not darkness, was the danger.

Nor could lights stop the great wrecks of the steam age. The White Star liner Atlantic misjudged her position on the way into Halifax in 1873 and drove onto the rocks with at least 535 dead, and the excursion steamer General Slocum burned in New York's East River in 1904 with 1,021 dead, most of them women and children, still the deadliest disaster in New York harbour.

What the Numbers Say

The test is the one used on the sister maps: for about 100 lights with a researched first-lit date, count the recorded losses within 10 and 15 km in the 20 years before and after the light was lit, and compare the 'after' number with what the trend for the whole coast predicted. Pooled, it lands within a few per cent of the prediction (5% below at 10 km, 6% above at 15 km). Near the lightships it was 11 to 14% below, near Canada's lights roughly a quarter below. Cape Sable had 48 wrecks nearby in the 20 years before its light and 30 after, when 63 were expected; Baccaro Point (1851) went from 65 to 32 when 81 were expected, and the Bishop and Clerks lightship in Nantucket Sound (1856) from 11 to none.

Near US lighthouses the count rose: 7% above the trend at 10 km, 37% above it at 15 km. Many were lit beside ports that grew far faster than the coast as a whole. Coney Island's light at the entrance to New York Harbor (1890) had 32 wrecks nearby before and 124 after, and Stepping Stones in Long Island Sound (1877) went from 1 to 14. A light does not prevent collisions in a crowded channel. And the American result is firmer than it looks: lights were usually built after a bad run of wrecks, which tends to be followed by a calmer one anyway, and even with that tailwind the US lighthouses show no drop.

Radio, Ice and the Long Decline

In this record the peak is the 1860s and 1870s, at about 70 recorded losses a year. The count does not fall when radio arrives: it stays at about 60 a year through the 1900s and 1910s, halves to about 36 a year in the 1920s and is down to a handful a year after 1950. What radio changed first was what a wreck meant. In January 1909 the White Star liner Republic, rammed in fog off Nantucket, stayed afloat for a day while her operator Jack Binns sent the CQD distress call; ships homing on the call took off about 1,500 people, and six died. After the Titanic struck an iceberg south of the Grand Banks in April 1912 and about 1,500 died, the first SOLAS convention brought lifeboats for all, round-the-clock radio watches and the International Ice Patrol. Two years later, in peacetime fog in the St Lawrence, the Empress of Ireland was rammed by a collier and sank in fourteen minutes with 1,012 dead, the worst peacetime wreck in Canadian history.

The years around 1900 need a warning. Between 1891 and 1913 Wikipedia's lists of shipwrecks are yearly instead of monthly. On this coast they keep the American wrecks (there are even more of them than in the 1870s), but the waters of Canada and Newfoundland almost disappear: from about 150 to 200 recorded losses in each five years of the 1870s to between 10 and 25 in each five years from 1895 to 1914. So when Halifax, Cape Race and the Newfoundland coast go quiet on the map between about 1890 and 1915, that is a gap in the record, not a calm sea. Whether the American coast really lost more ships around 1905 than in the 1870s, or the yearly lists simply lean on American newspapers, this record cannot say.

The world wars bring the last spikes. In December 1917 the munitions ship Mont-Blanc exploded in Halifax harbour and killed at least 1,782 people. Between January and August 1942 the map records 168 losses as U-boats worked along a coast that was not yet blacked out, picking off tankers silhouetted against the lights of seaside towns. The war itself brought loran (1942) and radar (the Andrea Doria and the Stockholm still collided off Nantucket in 1956, each having seen the other on its screen). The last US lightship left the Nantucket Shoals in 1983, GPS became fully operational in 1995, and in December 2023 Sally Snowman retired as keeper of Boston Light, the last American lighthouse with an official keeper, 307 years after Worthylake lit the first candles.

How to Read the Map

The hotspots are counted over the ten years before each date: orange for 0.25 or more recorded losses per 100 km², red for 0.7 or more, magenta for 1.8 or more. The thresholds are far lower than on the Irish and North Sea maps, so compare patterns between the maps, not colours. A yellow dot labelled 'lit' has a researched first-lit date; one labelled 'tower of' carries the year of the present tower, so the first light there may be older. The 87 pins tell the big stories; the small dots are a selection of about 1,200 wrecks, and clicking one opens its entry. The coast runs from 24° to 66° north, so the map opens zoomed far out on a wide screen.

Each wreck sits at the town, cape or shoal its entry names, so positions are approximate, and wrecks on large features such as the Grand Banks are spread over that area. The lists record only part of all losses, Canadian waters are thin between about 1890 and 1915, and after 1950 the empty sea means few recorded losses, not none.

How the Map Was Made

The wrecks come from the English Wikipedia's 'List of shipwrecks in …' pages (CC BY-SA 4.0), the same 245,000 entries we read for the North Sea map, placed by the coordinates of the places each entry links to. A link after 'departed from' or 'bound for' names a port, not the place of loss, so it was not used, and 695 ships sunk on purpose as blockships, targets or artificial reefs were left out. That leaves about 7,200 total losses and 3,900 other casualties. The 577 lights combine first-lit dates researched from lighthousefriends.com, Russ Rowlett's Lighthouse Directory and the US Coast Guard's lightship station index with OpenStreetMap lighthouses (ODbL) dated through Wikidata; only researched dates went into the analysis. The stories draw mainly on Wikipedia, the National Park Service, the US Coast Guard historian, Parks Canada and Memorial University's Maritime History Archive.

Chronological Timeline

• 31 July 1715 — Hurricane wrecks the Spanish treasure fleet off Florida
• 14 September 1716 — Boston Light, America's first lighthouse
• September 1775 — Hurricane kills at least 4,000 in Newfoundland
• 7 August 1789 — US Lighthouse Act
• 1848 — First federal money for life-saving, on the New Jersey shore
• 1860–1861 — The Hungarian lost off Cape Sable; Cape Sable lighthouse lit
• 1860s–1870s — Peak of the record: about 70 recorded losses a year
• 1878 — US Life-Saving Service made a separate bureau
• January 1909 — The Republic: first great rescue by radio
• 15 April 1912 — The Titanic sinks south of the Grand Banks
• 6 December 1917 — The Halifax Explosion
• 1942 — U-boats off the American coast; loran
• 1983 — The last US lightship leaves the Nantucket Shoals
• 30 December 2023 — Boston Light's last keeper retires