," Rick observed. "But what else can we try?"

Scotty thought it over. "Listen, we'll take the boat out right now.
You'll have to do the diving, because you know about where the thing is,
and I don't. When we get out, you go over the side. I'll run around to
the river, opposite where the guards are standing, and raise a little
fuss. That might draw their attention away from the cove."

"Okay." It made sense to Rick. "They'll see both of us in the boat, but
they won't see me get out. Only you'd better plan our course. I have no
aching desire to collect a rifle slug where it hurts."

"They may not shoot if they see we're leaving," Scotty pointed out.

"Uh-huh. And they might shoot, anyway."

"They might. But we'll be moving fast, and I'll swing that boat from
side to side like a swivel-hipped fullback. Let's get going. We don't
want too much daylight."

Scotty unsnapped his harness and Rick took his pal's tank and regulator.
They put Rick's unit in the bottom of the runabout cockpit, along with
Scotty's fins and mask. Rick put on his own fins and made sure he was
ready to hit the water at a moment's notice.

Rick went to the stern of the runabout and felt down the motor leg to
the prop to make sure it had not picked up any grass that might slow
them down. It was clear. Scotty, meanwhile, untied the boat and slid
into the driver's seat. Rick reached over the transom and pumped up the
gasoline tank to ensure plenty of pressure, then he waded to the side of
the boat and got into the seat next to Scotty.

"Pull us out to where the nose is almost projecting beyond the grass,"
Scotty whispered.

Rick did so, by grasping clumps of marsh grass and pulling the boat
along. As the bow cleared the grass, Scotty punched the starter button,
threw the runabout into gear, and shoved the throttle all the way
forward.

The runabout jumped forward, slamming Rick back against his tank. The
boat hit the shoal at the entrance and slowed for a long, breathtaking
moment, then the driving prop pushed it over into deeper water. The
stern went down and the bow lifted, and they were clear.

Scotty swung the boat to the right, putting its stern to the cove. Rick
tensed, expecting any moment to feel the impact of a rifle bullet,
either in the boat or in his own body. There was no sound other than the
racing motor, and he knew it would drown out the crack of a distant
rifle.

The distance from the cove entrance widened. "Get ready!" Scott