He brandished the revolver threateningly.
Frank obligingly increased the speed of the Sleuth but the rocking motion only became more pronounced.
The stranger gulped, but he did not lower the weapon.
"That's better," he said, without enthusiasm.
"I'm going to give him something to be seasick about," whispered Frank.
Without warning he suddenly bore down on the wheel and swung the motorboat about so that it was lying broadside to the waves.
"Here—what's the matter?" asked the stranger. "Where are you going now?"
"We're off our course. I'm heading in toward shore a little more so we can get out of the wind."
This explanation satisfied the stranger, although it became speedily apparent that the new course did not.
The Sleuth received the full force of the long rollers. The waves were not high enough to be dangerous, but the swells gave an undulating motion to the craft that swiftly increased the stranger's illness.