The biscuit is believed to be one of only two in existence – the other is in the Cobh Heritage Centre in County Cork, Ireland.
Accompanied by a handwritten letter from a Royal Engineer soldier who said he got it from one of the Lusitania's boats at Queenstown, was estimated at £3000-5000.
Made from flour, salt and water, cracker-like sea biscuits are designed to be long-lasting and were often packed on long journeys at sea.
The ocean liner RMS Lusitania, briefly known as the world's largest passenger ship, was sunk on May 1915 by a German U-boat 11 miles (18 km) from the coast of southern Ireland.
The 104-year old biscuit was bought by a private collector from Europe.
Also featuring in the April 27 sale in Devizes were a number of items that survived the Titanic disaster including a silver brandy flask belonging to author and women's rights campaigner Helen Churchill Candee.
The flask, estimated at £50,000-80,000, was hammered down at £62,000. Engraved with the Churchill family arms, the flask was given to Churchill Candee’s friend Edward Kent - a fellow first-class passenger – who she believed was more likely to survive the sinking than her.
However Kent's body was later recovered by the crew of the CS Mackay-Bennett and among the items sent back to his wife was this flask. Churchill Candee survived the sinking and later received the flask back as part of a package from Kent's grieving sister Charlotte.
The flask previously sold at Henry Aldridge & Son in September 2005 when it had been consigned by descendants of Churchill Candee. The sale last month was the first time it had been offered since. It was bought by a collector in the UK.
A rare silk Hands Across the Sea postcard, written onboard the Titanic by third-class passenger Henry Olsen, was another highlight at the auction. Postmarked Queenstown April 11, the auction house said silk examples of postcards written onboard the ship are “virtually unheard of and this is one of the rarest of this type”. It was hammered down at £30,000 by a Titanic postcard collector in Singapore against an estimate of £15,000-20,000.
A cast brass SS Titanic lifeboat plaque, inscribed on the reverse lifeboat number 12, was originally purchased in the early 1960s by a New York antiques dealer from an elderly woman believed to be third-class survivor Margaret Devaney. On offer at the April sale, the auction house noted that Titanic expert Walter Lord “gave his verbal authentication to the plaque prior to its original sale in 1987”, referring to an auction of Titanic memorabilia at Onslow's Auctioneers in London. Estimated at £25,000-35,000 at the April 27 auction, it sold for £36,000 to a Californian collector.
The sale was the first for new entity Henry Aldridge & Son Ltd. Andrew Aldridge relaunched the business following the retirement of his father Alan Aldridge in March. Andrew said the sale took a hammer price in the region of £300,000 and was a “pleasing start for the new company”.