"The rascal, or rascals, must be still at work, by Jove!" ejaculated Whittinghame. "Have your knives ready in case there's any resistance."
"We have something better than that, sir," said Dacres, holding up an instrument resembling a tuning-fork. "These are issued with the diving-suits in case the divers are attacked by sharks or human beings."
"What is it?" asked Whittinghame curiously.
"Be careful, sir," cautioned the sub as his chief stretched out his hand to take hold of the weapon. "It is electrically charged, and will temporarily paralyse any living thing it touches with these two barbs. My friend Commander Hythe had a dose of it once. He said he will never forget it. It simply knocked all the stuffing out of him."
"A good substitute for the 'cat,' then," commented Whittinghame. "Now, all ready?"
The metal headpieces were placed over the wearer's heads and clamped on to the collar-plates. The two men, deprived of the outside air, were now dependent solely upon the supply contained in the portable reservoirs.
Dacres led the way. Shuffling awkwardly to the entry port he made his way slowly down the ladder till the water reached to his shoulders. Then releasing his hold he sank gently to the bed of the Zandovar Harbour.
Fortunately there were no tidal currents. The bottom was composed of fine gravel and sand, and practically destitute of marine growth. The depth being less than thirty feet, the brilliant sunshine penetrated the clear water with very little loss of intensity.
The sub waited till the Irishman joined him, then pointed significantly towards the after end of the floating airship, whose rounded hull could be traced through almost its entire length.
Callaghan raised his hand to signify assent, and slowly the two divers made their way aft.