"H'm! pretty clever of Sheldon," sneered a stout, unprepossessing boy, who
seemed to be always scowling. "Knocks the kid overboard, and then goes to
his rescue to make himself solid with the father. Very clever stroke,
that, and just like him!"

"If you say anything like that of Jack Sheldon, Pete Herring," stormed
Dick, who had heard the ill-natured remark, "I'll knock you overboard!"

Herring, who was by no means a favorite in the Academy, quite the reverse,
in fact, had not supposed that Percival had heard his uncalled for and
utterly false assertion, and now hurried away with a snarl, evidently
fearing that Dick would carry out his threat.

The captain, as soon as possible, gave orders to stop the engines, and to
hold the yacht near to the place where the boys had gone down, being ready
to turn and go to their assistance when they should appear again.

All was excitement on board, for, until now, nothing had happened out of
the ordinary, and no one thought of being seasick or of complaining of the
monotony of the voyage.

Jack came to the surface, looked around him, saw young Jesse W. just
coming up and shouting for help while he swam, and then, not far behind,
what had caused him to take the knife with him, the sharp dorsal fin of a
good-sized shark moving rapidly through the water.