You are uncomfortably reminded once more of that inherited dislike of death by suffocation. If a submarine cannot rise to the surface, you ask, is there no possible means of escape? The answer is that it may be possible, with great difficulty, to get out of the boat; but there is very little chance that you would survive. The lungs are not fitted to bear so great and sudden a change of pressure as that felt in passing from the boat to the water, and from the deep water to the surface. You are perhaps surprised; but the pressure of sea-water at 160 feet is equal to five atmospheres, or about 75 lbs. to the square inch. To pass safely through this to the ordinary surface atmosphere would need a long and gradual process, and not a sudden rise of a few seconds. A very brave attempt was made on one occasion, when a British submarine had gone to the bottom during her trials, and could not be got up by any effort of her crew. The agony of the situation was intensified by the fact that help was close at hand, if only the alarm could be given, and the whereabouts of the submarine communicated to the rescuers. The officers of the sunken boat were, of course, perfectly aware of the danger from sudden change of pressure; but one of them volunteered to go to the surface, alive or dead, and carry a message on the chance of attracting some ship’s attention. To lessen the risk as far as possible, it was arranged that he should go up into the conning-tower, and that the hatch should then be closed beneath him and the water gradually admitted. As it flowed slowly in, and mounted round him, the air in the top of the conning-tower would diminish in extent but increase in pressure. When it reached his neck, the internal pressure would be nearly equal to the external. He would be able to open the top, possibly to make his escape, and conceivably to reach the surface without his lungs being fatally injured. If he failed, he would at any rate have given his life for the chance of saving his comrades.
The Commander accompanied him into the conning-tower, meaning, it is said, to return into the ship himself when he had seen to all the arrangements. But when the water was admitted, the two of them were shot out together, and as it happened it was the volunteer who was killed, by striking against the superstructure, while the Commander came up alive. In no long time--though it must have seemed unendurably long to those below, waiting in complete uncertainty--the rescuers were informed, found the submarine, and got a hawser under her stern. They raised her high enough out of the water, vertically, to open a hatch and save the crew. Then the hawser gave, and the boat went down again.