So HMS Invincible's loss in the Solent in 1758 as she headed for the Atlantic and action in Nova Scotia was a bitter blow.

For centuries she lay buried in the silt, until in 1979 Portsmouth fisherman Arthur Mack snagged some timbers in his nets on a sandbank in the eastern Solent.

He found a large tree-nailed frame off Horse Tail Sands and the site was soon explored by local divers Jim Boyle and John Broomhead, who reported a structure almost 200 feet in length with decking and artefacts exposed.

The team was joined by Commander John Bingeman, who was running a local dive team, and his friend Margaret Rule, who oversaw the raising of Mary Rose, was appointed as archaeological director.

Their first task was to correctly identify the vessel that they had found.

The suspicion that the team had discovered the final resting place of HMS Invincible was confirmed when Cdr Bingeman excavated a sail tally inscribed with 'Invincible, Flying jib 26 x 26 No 6'.

Later, a quoin used for gun elevation was found that was also inscribed with the name of the ship.

In September 1980 HMS Invincible was designated as an historic shipwreck under the Protection of Wrecks Act 1973.

A 10-year project saw almost 3,000 artefacts rescued by divers, many of which ended up at the historic dockyard at Chatham in Kent.

Other artefacts were sold at auction in order to fund further work – those involved were spending large sums of their own money on the project.

Now, 30 years after Arthur Mack's chance discovery, Hampshire and Wight Trust for Maritime Archaeology project officer Brandon Mason is calling on volunteers to help create a new online Invincible archive.

The trust says it's a great opportunity to get hands-on with history – Invincible has been described as one of the nation's most important post-medieval shipwrecks.

The aim is to digitise and preserve more than 7,000 individual documents, from site plans to dive logs, artefact drawings and photographs and underwater images.

Brandon also hopes to get some film taken of dives on the wreck and post them on a website so people around the world can see the scope of items rescued from the wreck of Invincible.

Brandon says: 'Until recently the vast quantity of documentary records has not been as easy to see.

'But now we have support from the Heritage Lottery Fund the trust has been making this research archive available by copying, sorting and digitising dive logs, site plans and artefact records.

'This is a fantastic opportunity to learn about a magnificent ship that was way ahead of Royal Navy technology when it was captured from the French.'



The elite fighting ship of her day

HMS Invincible began life as the French warship L'Invincible and was launched at Rochefort, France, in 1744. With two decks, 74 guns, and a crew of 700 she was the elite fighting ship of the day.

Her firepower could outmatch all but the largest three-deck warships and was coupled with the speed and agility of much smaller vessels, making L'Invincible a far superior design.

These 74-gun ships were to become the backbone of the British fleet for more than half a century and 16 such vessels were at the battle of Trafalgar in 1805.

In 1747 L'Invincible was escorting a French East India convoy to India that was intercepted by a British squadron led by Admiral Anson off the north coast of Spain.

Though hopelessly outnumbered, Captain St Georges' crew fought valiantly and L'Invincible was the last ship to strike her colours at the Battle of Cape Finisterre.

As a British prize, HMS Invincible was the flag ship of three Admirals, took part in two French wars and served as far away as the West Indies and Nova Scotia.

HMS Invincible was highly valued, with prize money paid by the Admiralty estimated at a modern equivalent of £60m, roughly twice the cost of a new vessel. The reason: Admiral Anson foresaw that this was the model for the next generation of fighting ships of the Royal Navy.

Despite seeing little combat, the ship's powerful attributes meant that her 14-year sailing career included a variety of roles from flagship to fast troop transport.

On February 19 1758, Admiral Boscawen's fleet set sail from Portsmouth for Nova Scotia in Canada to try to take the French fort of Louisbourg for the second time.

Invincible was to take part in this successful mission, but never left the Solent. After a calamitous series of events she ran aground on Dean Sand. Despite continuous attempts at refloating, the hull was flooded and fell over on the beam ends in gale force winds with seas breaking over the top.

After all that could be salvaged was retrieved, Invincible settled into the sandbank and became entombed for the next 221 years.

An exhibition of the Archiving HMS Invincible project will open at the Underwater Archaeology Centre, Fort Victoria, near Yarmouth, Isle of Wight in early March and will run throughout 2009.

The display will feature the story of the ship and the development of the digital archive and will include artefacts and underwater footage from the original excavation.

>>> Find out more at: underwaterarchaeologycentre.co.uk


Treasures beneath the waves

The Hampshire and Wight Trust for Maritime Archaeology is a charity that promotes interest, research and knowledge of maritime archaeology and heritage in Great Britain, with activities concentrated in Hampshire, the Isle of Wight and adjacent parts of the south coast.

Since 1991 the HWTMA has worked to preserve and record submerged landscapes, shipwrecks and sites of national scientific archaeological interest.

The trust runs a programme of research-led fieldwork involving professional archaeologists, volunteers and students. The results of this work are made available through a programme of educational initiatives including lectures, seminars and publications.


HOW YOU CAN GET INVOLVED

The Hampshire and Wight Trust for Maritime Archaeology is offering people the chance to see the shipwreck archive up close, in exchange for helping to organise and digitise it.

Brandon Mason says: 'The work involves the digitisation of these documents and their incorporation into an image database. It will be part of an internationally-available archive hosted at the site http://ads.ahds.ac.uk by the middle of this year.

'It will also be the basis for an interactive disc that will be available as a research tool in its own right.'

The archive is based at the trust's offices in Southampton, and all training and resources will be provided. There is also money available to help with travel costs.

To get involved, contact project officer Brandon Mason by phone (023) 8023 7300 or e-mail to brandon.mason@hwtma.org.uk

>>> For more information about the trust visit: hwtma.org.uk