he stared out into his watery
kingdom. Apparently the fish had no idea that the boys were in the
cabin. When it came time to leave and they touched him or hooted at him,
he would get the surprise of his life.

Even in their predicament, Rick could see the humor in the grouper's
reaction. He wondered if groupers were subject to heart failure from
shock.

Rick returned to trying to imagine the movements of the frogmen. Now
they would be cautiously boarding the _Water Witch_, one up the ladder,
the other climbing the anchor chain. They would be careful, still unsure
whether or not the quarry was aboard.

He thought he felt constriction in his lungs from the warning signal
that his air was running out, but finally decided it was only his
imagination.

Now the frogmen would be aboard the _Water Witch_, making a quick
search, spear guns ready to fire their lethal shafts. Now they would be
in the cabin and shouting their disappointment.

Now the frogmen would be hurrying back into the water, readjusting their
face masks, ready to dive.

The grouper shot out of the cabin with a flick of his powerful tail that
raised the silt around them.

Rick's heartbeat faltered. The grouper had been alarmed. They had
mistimed!

Right now, the frogmen were outside the _Maiden Hand_!

CHAPTER XVIII

The Fight on the "Maiden Hand"

They had only one hope now--that the frogmen would make a quick survey
of the wreck, then go away. The boys waited tensely, ears alert for any
sound that would tell them the whereabouts of their enemy.

There was only the sound of their bubbles.

Rick pressed close to the opening and peered out. The water that could
be seen from the entrance was clear. However, it was only a narrow
sector. For all he knew, the frogmen might be right overhead.

He backed down into the cabin and pushed his camera into a corner. He
could get it later. Right now he preferred to have both hands free. He
wished for a spear gun, to double their armament. But the other guns
were on the _Water Witch_. The wrecking bars were useless, too. It was
almost impossible to strike a blow against the resistance of the water.

Something scraped outside, and both boys froze. There was no doubt that
the frogmen were at the wreck. Why didn't they go away? They couldn't
know about the entrance to the cabin--or could they?

The moments dragged by. There couldn't be much air left in their tanks.
Rick risked holding his wrist close