"Lot of good a turned-off radio would have done," Rick muttered. Barby glared. "We decided that we'd go swimming with the lungs. Then we'd come up right next to the houseboat, and we'd be so surprised! Of course the people would come out to see us, then we'd say I had a cramp, and could we please come up and rest." Rick listened, and he had to admit it wasn't a bad plan at all--so far. "Of course they would let us rest. Then I'd wait for a chance to put the radio behind a cushion, or in the crack of an armchair, or somewhere like that. I didn't know exactly what I could do, but I knew if we could get aboard there would be some way of leaving the radio behind." The pram had vanished around the turn of the cove. The speedboat would come into sight any moment now. "All right," Rick admitted. "Let's say it was a good plan. What happened?" Jan took up the tale. "We didn't want to try to swim all the way from Spindrift, so we took the rowboat and did exactly what Cap'n Mike did yesterday. We rowed along the shore with the aqualungs and got into the water right where we could see the houseboat. We had to. Otherwise, we would have gotten lost underwater." "But you had the wrist compasses, didn't you?" Scotty asked. The boys had stressed that compasses were essential because low visibility in the waters off Spindrift made it very easy to lose one's sense of direction. "We had the compasses," Barby said. "How do you think we swam right to the houseboat?" "Then why didn't you get into the water out of sight of the houseboat?" Rick asked, and suddenly he knew. That would have meant plotting a compass course around a turn. So many feet in one direction, then change to another compass heading. He had explained it to them, but they just hadn't learned. It was not easy, he had to admit, and it took practice even on land. "Never mind," he said. "I know the answer. Go ahead. Tell us the rest." Barby studied his face. "I guess you do know," she assented. "Well, they told us later, on the houseboat. They saw us get into the water, then they watched our bubbles come right toward them. So when we got here, they weren't fooled." "We went through with it, as we planned," Jan said, "and we thought we were getting away with it. They were very nice. Of course we could come up and rest. They were glad to have us stop by. But when we got aboard, one of the women had a gun, and she made us go into the cabin and sit down. Then they started asking us questions." "What kind of questions?" Rick inquired. "About why we had come. We stuck to the story, until they told us they'd seen us. Even then we didn't admit anything. Then Barby started to threaten them." Scotty chuckled. "I'd like to have heard that." Rick watched the tip of the cove. The speedboat from Spindrift should be coming shortly. "How about the plane?" he asked suddenly. "What did you do with it?"