Accordingly, when the heat of the day showed signs of abating, the diving-party proceeded to the spot. Swaine, clad in his diving-dress, sat in the stern sheets nursing his copper helmet. As the outfit was self-contained there was no necessity for the cumbersome air-pump and pipe. A wire-rope ladder and a shot-line and distance-rope comprised all the gear necessary for lowering from the boat. During the week that had elapsed since Dick's adventure, Jack Villiers had been undergoing a diving-course. Already he had made good progress under the experienced Swaine's supervision, and although he had not yet reached a depth of fifteen fathoms he was ready, if need were, to descend to his comrade's assistance should anything go wrong. "You'll have to watch the current," observed Harborough, as the boat swung to her anchor. "Better to work against it than with it on a job like this." "Right-o, sir!" replied Swaine, as his assistant prepared to complete the hermetically-sealing process by placing the copper helmet on his head and screwing down the front and side plates. Encumbered with leaden-soled shoes, slabs of the same metal fixed to his chest and back, and wearing his chemically-created air-reservoir and a diver's electric lamp, Swaine was helped over the gunwale. Awkwardly he descended the rope-ladder, till the water reached the level of his shoulders. Then, raising his bare hand in a gesture of farewell, he disappeared beneath the surface, leaving a trail of air-bubbles to mark his descent. Swaine had declined to take the portable telephone with him on the preliminary descent, objecting on the grounds that it would hamper his movements. On the other hand, Harborough had strictly enjoined him not to attempt to enter the hull of the wreck, but to content himself with an examination of the hull and report upon its position and condition. The moment the diver reached the bed of the lagoon all communication with him was cut off. All he could do was to advance as near as possible in a straight line, paying out his distance-rope as he plodded through the ooze until he reached the wreck. The watchers in the boats could note the trail of air-bubbles as Swaine walked away from the shot-rope. The bubbles were the only indications of his presence and of the fact that the life-sustaining apparatus was still working. "He's progressing against the current," observed Bobby Beverley. "Perhaps it's only a surface-current," rejoined Harborough. "If so, so much the better. Sharks? No, I don't fancy they'll dare attack a diver. They'd be more frightened than the man. An octopus is another proposition. They are apt to be found in weed; but they don't grow to any very large size in these parts."