Descendents of passengers who died when a German U-boat attacked the P&O liner, SS Persia, more than 90 years ago, have praised the new exhibition at Buckler's Hard as "a permanent memorial'' to those who were lost following the torpedo attack.

For David Conran-Smith and his sister, Caroline Hill the exhibition had added poignancy as their grandparents were both killed in the attack on the ship.

"They were Marcel and Hilda Conran-Smith, who were both in their 30s and on their way back to India after taking their young six-year-old son, Louis back to England for his education,'' said Mrs Hill.

"The family had long been established in India and my grandfather's work was in connection with telegraph communications but they were not able to survive the sinking.

"I like to think that this exhibition will be a permanent memorial not only to our grandparents but also to the many others who went down with the ship.'' Also at the exhibition's official opening was the grandson of Eleanor Thornton, Richard Moorby, who described his grandmother as a "most ambitious'' person.

Without warning an enemy torpedo had slammed into the hull of the ship and immediately Persia began to list to port. Passengers were trying to collect lifebelts and make their way to the lifeboats but the launch of these craft were hampered by the incline of the deck.

People were washed into the sea as the deck became too steep to walk along. The ship capsized and five minutes after the explosion Persia's funnels slipped below the waves.

John, 2nd Lord Montagu and Eleanor Thornton, his secretary and mistress, who was also known as "Thorn'', were sitting in the First Class dining salon when the torpedo struck. As the couple went to save themselves a wall of water engulfed the deck, ripping Thorn from Lord Montagu's grasp.

The ship disappeared into 8,400 feet of water and remained undetected until 2001 when Deep Tek, a company owned by Alec Crawford and his wife, Moya, began work on the wreck.

Highly sophisticated equipment was brought to the site in what had become the world's deepest commercial salvage operation inside a wreck. The target was Persia's bullion room said to contain huge amounts of gold and jewels but none was ever found.

Visitors to the exhibition will see many of the ship's artefacts, entombed since it's sinking, and now on display for the first time. Included are personal items such as clothing, shoes, pipes and pens together with a number of articles that would have been used on board.

Even the heavy metal door to the liner's bullion room has been recovered and is now one of the major centrepieces of the SS Persia exhibition.