business to," growled Sam; "he ought to be attending
to his work instead of showing a lot of nosy young cubs my new boat."

"They are capable of stealing your ideas," chimed in Jack Curtiss, "and
putting them on their own boat."

"That's ridiculous," laughed Rob, "as I said I wouldn't want to have
anything to do with such a contrivance except on a lake or a river."

"Well, you keep your advice and your ideas to yourself, and get out of
this yard!" roared Sam, waxing bolder and bolder, and mistaking Rob's
conciliatory manner for cowardice. "I've a good mind to punch your
head."

"Better come on and try it," retorted Rob, preparing for the immediate
onslaught which it seemed reasonable from Sam's manner to expect.

But it didn't come.

Muttering something about "young cubs," and "keeping the boat-yard gate
locked," Sam turned to his chums and invited them to come and try out
his new motor in the shop.

As the three chums had no desire to "mix it up with Sam on his own
place," as Tubby put it, they left the yard promptly, and walked on
down the water-front to the wharf at which lay the Flying Fish, the
fastest craft in the Hampton Motor Boat Club. Rob's boat was, to tell
the truth, rather broad of beam for a racer and drew quite a little
water. She had a powerful motor and clean lines, however, and while
not primarily designed solely for "mug-hunting," had beaten everything
she had raced with during the few months since the boys had completed
her. The money for her motor had been given to Rob by his father, who
was quite indulgent to Rob in money matters, having noticed that the
lad always expended the sums given him wisely.

"Let's take a spin," suddenly suggested Tubby.

"Nothing to prevent us," answered Rob; "we've got plenty of time before
dinner. Come on, boys."

The lads were soon on board and examining the gasoline tank, to see how
much fuel they had on hand, and oiling up the engine. The fuel
receptacle proved to be almost full, so after filling the lubricant
cups and attending to the batteries, they started up the engine--a
powerful, three cylindered, twelve-horse affair capable of driving the
twenty-two foot Flying Fish through the water at twelve miles an hour
or better.

Just as Rob was casting off the head-line there came a hail from the
wharf above them.

"Ahoy, there, shipmates! Where are yer bound fer this fine, sunny day?"

The lads looked up to see the weather-beaten countenance of Cap