Museums around the UK will have the opportunity to display rare artefacts salvaged from protected wreck sites that have been saved from auction by the Maritime Archaeology Sea Trust.

The trust, which works to ensure a sustainable future for underwater maritime heritage sites, struck a deal with the privately owned Charlestown Shipwreck & Treasure Museum to acquire the most important artefacts in its collection before they went to auction earlier this month.

It was announced in August that the museum building and its contents would be put up for sale by Smit Associates, a group of companies in Cornwall owned by the Eden Project co-founder Tim Smit. 

The collection of around 8,000 shipwreck and maritime artefacts was put together in the 1960s and early 1970s by the famous wreck diver Richard Larn. It has been described as “practically impossible to duplicate” following Unesco’s introduction of a ban on diving wrecks up to 200 miles offshore.

The planned sale led to fears in the heritage community that the unique collection would be dispersed and lost to the public.

On the eve of the sale, which took place on 6-7 November, the Maritime Archaeology Sea Trust (Mast) reached an agreement with the museum to prevent 500 of the most significant artefacts in the collection from going to auction.

Salvaged from protected wreck sites, the 500 artefacts have been identified by Historic England as the largest and most important collection of objects from shipwrecks in the UK.

The material was retrieved from 12 Designated protected wrecks with the same status as the Mary Rose, including Royal Navy warships such as HMS Ramillies, HMS Association and English and Dutch East India Company wrecks.

Mast is planning local and national opportunities with museums around the UK to share and learn from the collection, which it says “not only tells the story of the development of maritime archaeology in the UK but also the history and archaeology of the Royal Navy and the development of international trade”.

The trust has been supported by the National Museum of the Royal Navy and Chatham Historic Dockyard Trust.

“I’m delighted and relieved in equal measure that Mast has been able to save this priceless collection that can tell countless stories of the history and archaeology of the Royal Navy and the development of global trade through the centuries,” said the trust's CEO Jessica Berry. 

“Mast has now taken the collection out of private ownership so its risk of being dispersed again has now gone forever.”

Smit said: “We, at the Shipwreck & Treasure Museum, are delighted that Mast is buying the artefacts from what are now protected wrecks, saving a unique collection for the nation. It is especially pleasing as Mast is made up of members who themselves have dedicated so much of their lives to exploring our underwater heritage.”

The remainder of the museum's collection went under the hammer earlier this month, attracting more than 2,000 bids from bidders all around the world. One model ship sold for £5,800, while a lump of coal salvaged from the Titanic fetched £1,800.

A spokesperson for Lay's Auctioneers, which undertook the sale, said: “Although controversial locally, the sale of the museum was a pragmatic decision by Tim Smit, its owner. It is a large damp, granite building and many of the most sensitive historic artefacts were deteriorating.

“Although the popular museum paid its way, it didn't generate the capital investment needed to refurb the building and purchase much-needed climate-controlled cabinets. Smit, a wreck diver himself, said it was always a priority to keep the collection together if he could.”

The museum building is being sold through SBC Property with an asking price of £1.5m.

Mast was founded as a charity in 2011 by the maritime archaeologist and author Jessica Berry, to protect maritime underwater cultural heritage through archaeology, research, study, dissemination and education.