a
communicative mood.

"A shift of wind. It's blowing great guns up aloft, and there's a
terrific tumble into this channel. We've dragged, or, rather, swung
round our anchor."

"But we are safe enough?" asked Vernon.

"Yes, safe," replied Hans. "Too safe; we cannot break out our anchor.
They are sending a diver to see what is amiss."

Evidently the diving arrangements on board were not considered to be of
a confidential nature, for Hans led the way to the compartment under
the fore-hatch, without the lads being sent back by the significant
word "verboten".

A man was preparing for a submarine walk. He was already dressed in an
india-rubber suit, with leaden weights attached to his chest, back, and
boots. Two others were standing by, ready to place the helmet over his
head, when Leutnant Rix had finished giving him minute directions.

The officer spoke rapidly and in a low tone. Ross could not catch all
he said, but the words "gefaehrliche Stroemungen" (dangerous currents)
and "Der Wendepunkt der Flut" (slack water) and "Drei Viertel funf" (a
quarter to five) occurred frequently.

Vernon glanced at his watch. It was then a minute after four.
Apparently Rix was impressing upon the man that he must clear the
anchor at slack water, which occurred at a quarter to five.

The two attendants then proceeded to place the diver's helmet on his
head. The lads noticed that it had neither air-tube nor telephone
wire. Nor was there a life-line attached to his waist. Fresh air was
obtained from a metal case strapped to his back. The man was able to
work independently, and without having to rely upon his air supply from
the submarine.

The oval door in the diving-chamber was thrown open. The diver
entered, and the water-tight panel was quickly replaced. One of the
seamen thrust over a short lever, and immediately water rushed into the
small compartment. As soon as the space was filled the diver was able
to open a similar door in the outer plating of the submarine, and thus
gain the bed of the sea.

Presently Leutnant Rix turned, and saw for the first time that Ross and
Vernon were discreetly standing in the background.

"Go away. It is forbidden!" he shouted angrily.

They obeyed promptly, retreating to the space allotted to the crew,
since it was neither desirable nor possible to return to their bunks.

For some minutes the luckless Hans Koppe was subjected to a severe
dressing-down by his hot-headed of