‘2 full, sir,’ said Hoskins. A pause, and then ‘3 full, sir,’ he added.

‘How is she now, coxswain?’ asked the captain again.

‘Two degrees by the stern, sir.’

‘Thank you. Close main vents. Another 500 in the fore trim, Seagrave.’

‘Ay, ay, sir; 500 in the fore-trim,’ repeated the ‘Sub.’

‘Horizontal, sir,’ from the coxswain.

The needle of the depth-gauge trembled, moved slowly, reached four feet and stopped.

‘Four feet,’ announced Seagrave.

‘That’ll do,’ replied Raymond. ‘10,000 in the auxiliary and flood the buoyancy.’

The depth-needle shivered and crept on to ‘fifteen.’