what's
goin' on. But if that's any filibustin' outfit, they'd better make
tracks out o' these waters as fast as they can lay beam to wind'ard."

So saying, he shifted the helm again and bore away at an angle that
would enable them to come close to the revenue cutter, now scarcely
a quarter of a mile astern. Lighter and lighter came the wind,
slower glided the _Arrow_ over the long heavy swells, nearer and
nearer came the cutter, going at a steady, rapid rate. Soon the two
vessels were within hailing distance, and a megaphone call came
across the water, clear and distinct:

"Sloop, ahoy! Can you understand?"

"Aye, aye!" called Vinton.

The five boys gathered around him, eager to hear the interchange of
calls. Even Dave rose and shambled over to the little group at the
tiller. On the other vessel they could now see a number of men in
blue uniforms and one in a civilian's suit of gray tweeds.

"Who've you got aboard?" came the next question from the captain of
the _Petrel_.

Vinton briefly stated his passenger list and explained the purpose of
their cruise.

"Bound for Key West now?" shouted the _Petrel's_ captain, whom
Vinton, studying him through the marine glass, recognized as James
Kelsey. "Trying to dodge that craft that just passed us, or trying
to catch her?"

"We were goin' to report as how we seen her las' night off Snipe
Point," bawled Vinton, speaking through a megaphone which Dave had
handed to him. "Thought you fellows were at Key West."

"We were until this morning," came the answer. "We've been chasing
that boat. She's the _Esperanza_, a smuggler. Have you seen her
throwing anything overboard, or picking up stuff---like boxes or
small kegs?"

Then a light of understanding broke upon Vinton's mind. So that was
what the smuggler had been doing all night! Not grappling for the
cable, but stealthily picking up a contraband cargo of munitions of
war, small stores such as could be cast adrift along the coast in
some prearranged method and gathered in by those who had been
instructed to recognize the floating objects! What were they?
Water-tight kegs of dynamite, submerged, but buoyed up by thrice
their weight of corks? Boxes of rifle bullets? Or merely harmless
glass bottles containing, perhaps, written descriptions of the country
to be invaded, photographs of fortifications, details of naval or
military equipment?

The answer was not long forthcoming.

"Ain't seen her pick up an