"There's quite an important little job for you up at Craven's Bay,"
continued Mr. Farnum. "You know, there are important fortifications
there, because the Navy people expect, in wartime, to use Craven's
Bay as a possibly important naval station and shelter for vessels that
have to put in. Now, for some time the Army engineer officers have been
perfecting a system of submarine mines for the bay. The engineers have
a problem on hand as to whether an enemy's submarine boats could sneak
into the bay and blow up the submarine mines before the Army woke up
to the danger."

"There's a chance that _that_ could be done," nodded Jack, musingly.

"Jest so," nodded Mr. Farnum. "So I want you to go up in one of the
boats. To-morrow the engineer officers at that station will test it out
with you whether a submarine can destroy the mines, or the mines could
be made to destroy the submarine boats."

"Then the Army engineer officers will use dummy submarine mines, I hope,"
broke in Eph.

"Oh, of course," nodded Mr. Farnum. "Now, the trip to Craven's Bay is
only an eight-hour sail at a good gait, so you won't really need to
start until after dark to-night."

"I believe I'd rather start now, though, and go at less speed," suggested
Jack, thoughtfully.

"That's just as you please, of course," nodded the shipbuilder.