der:

"Submerge to twenty meters!"

"Both engines half steam ahead!"

I was able to follow our submersion by means of the manometer.
Through flooding the tanks, the boat is given several tons
over-weight and the enclosed ship's space is made heavier than
the displaced quantity of water. The titanic fish, therefore,
began to sink downward in its element, that is to say, it began,
in a certain sense, to fall. At the same time the electric
engines are put into motion and the propulsive force of the
propellers acts upon the diving rudders and causes the sinking to
become a gliding. After the required depth has been
reached--something which may easily be read from the manometer
that records the depth--all further sinking may be stopped by
simply lightening the hull, which is done by forcing out some of
the water in the submarine's tanks. The furious growling of the
pump is always a sure sign that the required depth is being
approached. The noise ceased, only the electric motors continued
to purr, and the word came from the central station:

"Twenty meters--even keel!"

"Rudder set!"

So we forged ahead at a depth of twenty meters. Of course we are
"blind" under such conditions and can regulate our movements only
by means of the depth recorder and that precious little jewel of
the boat, our compass. No ray of light reached us any longer from
without, the periscope was submerged long ago and the steel
safety covers over the windows were closed. We had been
metamorphosed completely into a fish.[1]

[Footnote 1: (C)]

Orders were then given to rise again. The _Deutschland_ carried out
this manoeuvre with the same facility with which she had taken the
initial dive of her long voyage. In record time the ballast tanks
were emptied and the change from electric motors to oil engines was
completed without further loss of time. The boat was started at top
surface speed towards her ultimate goal, the United States.

On the following day the _Deutschland_ barely escaped running foul
of a British submarine chaser, disguised as a neutral merchantman. A
quick dive alone saved her. When she came up again a wild storm and
a heavy sea were raging. Even before the change from the electric
motors to the oil engines had been completed, another dangerous
looking vessel appeared and before long