George grinned. "That would be fun. I've never had one."
The girls said good-by to the captain and returned home. There was plenty of exciting conversation as they exchanged stories with Nancy. Mr. and Mrs. Cosgrove listened and were thunderstruck at all that had been learned.
"Each day you prove more and more what good detectives you are," their host complimented them.
"But we haven't solved anything yet," Nancy reminded him. She turned to George. "Did you ask Captain Smith about the periscope?"
"Oh dear, I didn't even think of that," George said. "But we can go back another time and inquire if he's ever heard of a sub around here."
Nancy wanted to go out in the skiff the following day, but Mr. Cosgrove said that he had had the craft out in the morning and found that it had been tampered with.
"It was lucky I discovered the damage before you used the Pirate again. You might have had a bad accident."
Nancy exclaimed, "You say it has been sabotaged? I'm afraid our enemies have been at work!"
The others agreed. Mrs. Cosgrove was worried. "This could mean that we're all being watched by spies. I think you should stay away from Crocodile Island for a while."
George grimaced. "At least until the Pirate is repaired."
"Meanwhile, why don't you visit Cape Florida?" their hostess suggested. "It's a lovely place. Beautiful trees and a nice beach. People go there for picnics. The main attraction is an old lighthouse. A guide will show you around and tell you something about its history."
"That sounds great," Bess said. "I could use a change of pace."
The girls got directions and set off early the next morning in one of the Cosgrove cars. Nancy, at the wheel, drove across the bridge leading to Cape Florida, and turned into the park entrance.
"Look at those gorgeous trees!" Bess exclaimed as they rode down an avenue of tall Australian pines.
"I've read in a magazine that these aren't native to Florida," Nancy said. "They were imported."
The road twisted and turned; then they came to a shaded picnic area with a large sandy beach.
"This is a heavenly spot," Bess remarked. "No wonder it's so popular."
Many people were seated oft the beach, while others had settled at picnic tables set up in a grove of trees. Nancy parked and the girls strolled toward the water.
To their right was a natural coral breakwater, which had been built up by polyps. It was very rough and Nancy realized at once that anyone slammed into it by waves could be badly cut. She noticed that bathers seemed to be avoiding it.
"What a lot of seaweed there is!" George remarked.
She picked up handfuls of it and rolled the soggy masses into a ball, "Let's play catch," she suggested.
The girls formed a triangle and threw the seaweed ball back and forth to one another. Whoever dropped it was eliminated from the game. After about ten minutes of play George was declared the winner.
To tease her, Bess picked up the ball and threw it hard at her cousin. Unfortunately it missed and sailed across the sand. The soggy mass landed plunk! on a bald-headed bather who was stretched out on the beach, sleeping.
"Oh!" Bess cried in dismay and went over to the man.
He blinked at her and looked annoyed, but after she apologized and he saw the look of concern on her face, he sat up and smiled. "Hi!" he said. "My, you're pretty!"
Bess backed away. "He's old and fat and bald-headed," she told herself. "I hope he won't try to get too friendly!"
Her fears were confirmed when the man stood up and took her hand. "I believe you threw that seaweed on purpose to wake me up. Well, here I am, at your service!"
"I—I—it was an accident," Bess stammered. Then she turned away and ran off as fast as she could. When she reached Nancy and George, they laughed.
"That'll teach you to aim straight when you throw something," George remarked.
Nancy, who had been watching various bathers in the water, now spotted a little girl who had not noticed that the tide was pulling her toward the coral breakwater. She realized that at any moment the child would be bashed against its jagged side and severely injured!
Nancy rushed down to the water's edge, slipped off her sandals, and splashed in. The water was shallow for adults, but the little girl could have drowned in it. Nancy swam with powerful crawl strokes toward her. By now the child was only a few feet from the breakwater!
"Come here!" Nancy called out and grabbed the child's hand. Together they struggled to the beach, where they were met by a frantic woman.
"Tessie!" she scolded, "You were told not to wade over there!"
The little girl cried. "I didn't mean to, but all of a sudden I couldn't keep from going that way," she sobbed.
"Are you her mother?" Nancy inquired.
"No. I'm Mrs. Turnbull. I'm in charge of a group of children who attend my day camp. I brought them here to swim, but it's hard to watch all of them at once."
"I understand," Nancy said.
"Thank you for going in after Tessie," Mrs. Turnbull continued. "When I saw her, it was too late for me to help."
Now the other children ran to them. The woman opened her purse and offered Nancy a bill as a reward for saving Tessie's life.
"Thank you," Nancy said, "but I couldn't possibly accept any money."
Tessie had stopped crying. She took Mrs. Turnbull by the hand, and said, "I know how we can reward her. Give her the map."
Mrs. Turnbull smiled. "Tessie, we have no right to give the map away. We should turn it over to the authorities. But I will show it to this young lady. By the way, what is your name?"
Nancy introduced herself and her friends, who had joined the group, by their Boonton name, not wishing to be identified. The woman fished in her handbag and brought out a faded piece of paper. She unfolded it.
"I don't know whether this is authentic or not," she said. "We found it back in the woods. Somebody must have dropped it yesterday or today."
Nancy, Bess, and George studied the map. Not only was the paper old, but the printing on it was quite faded. Mrs. Turnbull explained that she and the children suspected that someone had been hunting for a treasure, perhaps buried long ago by pirates.
"The person must have lost it. The map does seem to indicate a buried treasure," she said. "Perhaps it's here on Florida Key."
The girls were intrigued by the story, and Nancy looked closely at the map. On it were directional lines pointing north, east, south, and west. There were also a number of intersecting lines converging at one spot.
"This must be the place where the treasure was hidden," Nancy remarked.
"True," Mrs. Turnbull said. "But how would one go about trying to figure out where it is?"
"We have to find a point of reference," Nancy said. "But what?" She puckered her brows and tried to figure out the strange map. Suddenly the girl detective had an idea.
"You see this line running directly into the water? It could be the coral breakwater!"
"You're right!" Mrs. Turnbull agreed. "Let's draw a continuing line from it through the sand and then bisect it just as it was on the map."
Tessie jumped up and down in excitement. "Let's hurry up and dig!" she exclaimed. "I brought my sand shovel. I'll get it."
She ran off and soon returned with a toy shovel. Nancy, Bess, and George were amused at the thought of digging for hidden pirate treasure with this implement.
The bald bather had walked up, curious to see what was going on. When he realized that they were planning to dig with the toy shovel, he said, "I have a spade in my trunk and would be glad to lend it to you."
He hurried to his parked car and returned a few minutes later with the spade. He handed it to Bess and looked at her with an admiring smile. It made her blush.
"Thank you," she said and pushed the spade into the sand. She worked for a while. Then, when the hole was about a foot deep, she handed the spade to Nancy.