Like pairs of long-necked dinosaurs frozen in time, the gigantic lifeboat davits loomed above the divers. She imagined the lifeboats, each with seventy-five frightened passengers, swung out over the side of the ship, then lowered by the ropes. Would they see one? Or had all the lifeboats disintegrated? It was, after all, a hundred and five years since His Majesty’s Hospital Ship Britannic went to the bottom of the Aegean Sea.

‘I’ve never seen so much wildlife on a wreck,’ Shelly said.

‘That’s because they’re using rebreathers. There’re no noisy bubbles to frighten the shoals of fish away. The only noise you hear is from the motors of the propulsion vehicles, which the divers use as little as possible, in order to save the batteries and also because they enjoy the silence.’

‘Look at that. The divers appear so small against the propellers.’ She remembered Gertie’s description of the carnage they caused. ‘Amazing marine life growing on the blades too. Saddle oysters, marine crustaceans, yellow sponges, they’ve all taken up residence, just how big are they, Harry?’

‘The propellers? Twenty-four feet across and weighing thirty-eight tons,’ Harry said. ‘Can you imagine the noise, and the turbulence? They must have been a terrifying sight for those who saw them close up.’

‘Look, we’re seeing E deck from the outside. Those portholes are all open,’ Elias said. ‘Nobody was ever brought to justice for going against orders, were they?’

‘What’s going on there?’ Shelly pointed to a screen where the dive camera was clearly deep inside the wreck. ‘I thought there was only one video diver.’

‘There is,’ Harry said. ‘What you’re seeing is relay from an underwater drone. It’s operated by the one-man sub. There are two. He’s checking the watertight door between boiler rooms five and six. According to inquiry statements from the firemen, this door was jammed half open. Clearly, we can see it was all the way open. Nothing could have saved the ship with that open.’

‘Even if the portholes had been closed, the Britannic was doomed when that door jammed,’ the screen operator said.

Shelly wished her great-grandmother could have heard that statement.

The operator continued. ‘Anyway, better she went down when she did. Just imagine if she’d got to Lemnos and embarked four thousand sick and wounded soldiers.’

‘What’s he talking about?’ Shelly asked quietly.