The story of nine boys and their tragic deaths has been brought back to light by historian Ken Chamberlain, who has painstakingly pieced together their story.

The dead boys were all cadets from the Merchant Navy officer cadet training ship, HMS Worcester.

From 1862 until 1968, boys hoping to make a career in the Merchant Navy were educated on board a training ship moored in the Thames.

The first HMS Worcester, a former Royal Navy wooden frigate, opened to cadets in 1862 and spent its first year moored at Blackwall Reach.

In 1863, it moved down river and moored off Erith by the Pleasure Gardens now occupied by the Morrisons supermarket.

On board were up to 130 cadets getting a general education as well as learning seamanship from the 20 staff.

It was the last day of February in 1865, when several of the boys went ashore to be confirmed and the captain superintendent, George Whitby, decided to give the rest of the cadets a half-day holiday.

Staff organised a sail upriver and three boatloads of boys set off on their unexpected treat at 2pm.

By 3pm the tide had turned and the boats were approaching the Crossness sewage outfall at Belvedere.

On board one of the boats, carrying 21 of the cadets and commanded by the college's boatswain John Cashman, a cadet dropped his hat into the river.

Cashman ordered the boat to turn about so the hat could be retrieved from the water.

Tragedy struck as the boat turned. Without warning it capsized, throwing everyone into the water. Nobody was wearing a lifejacket and many boys could not even swim.

Panic broke out among the boys as they thrashed around in the water. As other boats on the river made their way to the scene, Cashman passed one boy up to a waterman. But he had been hit by the boat's mast as it capsized, and was dead.

Boatmen threw oars into the river, shouting to the boys to grab hold of them. One 14-year-old cadet, Errington Ord Denton, was a strong swimmer and he was spotted close to the bank holding up two boys.

But a third boy, in his panic, grabbed Denton's legs and that was the last time Denton was seen alive.

The Worcester also sent its own boats to the scene and, after a roll call, horrified staff discovered that while 12 boys had been saved, nine were still missing.

Four of the parents took their sons home for burial but five, including Denton, were buried in St John's churchyard in Erith, with full Naval honours after a funeral procession through the town's streets.

The others who died were Charles Johnstone, James Waller, John Newman Harrison, Walter Strickland, William Powell Stanton, Henry Barber, Joseph Ward Leigh, Hayter Bessemer Wonostrocht and Alfred Manders.

Mr Chamberlain has researched the boys' inquests and even traced Denton's family. He was recently invited to give a talk on the little-known tragedy to the Association of Old Worcesters who knew nothing of the catastrophe.