“Wear your hat!”
“Put on more sunscreen!”
“Don’t leave your brother behind.”
“Don’t do anything silly, and that means swimming at that side of the beach. You see that headland,” the adult pointed at a large jumble of rock that was one end of the beach, “there are dangerous currents coming around that corner of land and you mustn’t swim there. You could be pulled underwater or out to sea and there would be nothing we could do.”  The adult enjoyed scaring children into good behavior. “We would have to call out the Sea Rescue Helicopter and we might not find you for days... if we ever found you at all!”
The group of adults, having brought their families to such an exciting place, sat down and refreshed themselves. The four children pattered away, and came back. They wandered one way as a group, and the other way alone. They went down to the very edge of the vast sea, and ran quickly back when the waves chased them. Brodie found a stick, Zara found a crab. Sarah stood very close to the sea and stared out to the horizon, Kelly put her towel down a little away from everyone else and stared into the hot sky. Brodie filled his bucket again and again with wet sand and looked like he was going to build a wall of sandcastles from one edge of the beach to the other. Sarah watched her brother and the babbling group of grown-ups, neither was aware of the enormous beach around them. The adults looked at each other, little Brodie looked at his bucket.
The sun rose in the sky and the sand became a mirror, bouncing the light from the sky to the eyes. Sarah decorated a few turrets of Brodie’s Great Wall Of China. She dripped watery sand through her fingers creating delicate minarets, pointed tops to the towers. She carefully wrapped strips of seaweed, she gently pushed shells into place, she expertly hollowed out cosy basements for the tiny buildings. Zara bobbed on the ocean’s swell, sometimes treading water, sometimes trying out the various floats that she knew. Mushroom float was her favorite, if you relaxed and stared down hard into the water it felt as if you could hold your breath for ever. She held her breath as much as possible, keeping her eyes open to look for colourful or fast-moving fish.
The temperature rose and rose and first Kelly and then Sarah ran into the welcoming, cooling water. They hurled themselves into the roaring, swirling white waves and shrieked with joy. Each wave seemed bigger than the last, sometimes it knocked the girls from their feet and they got up coughing and laughing so hard that the next wave knocked them over again. Brodie remained on the hot sand, the sunhat he hadn’t wanted to wear was now forgotten on his head. He forgot about building sandcastles and he forgot all about the other children, as they had forgotten about him. All he remembered was the stick that he had found and its possibilities if he could find it again.
Kelly swam out into the sea. Out of her depth so that she couldn’t touch the bottom. She swam out to where the waves were bigger, so big that you had to swim through each one as it rushed at the shore. Kelly tried to keep her eyes open inside the waves, to look up into the weird shapes of smashing water. She could feel the power and weight of each wave as it rushed by above her and the force of their passing made her think about how small she was compared to the sea. She surfaced like a cork to find that Zara had swum competitively out to near her. For a moment she worried about her sister but she knew not to say anything. “I’ll race you to the shore.” She cried, trying to keep everybody safe, and dived forward into a fast front-crawl.
Zara took a huge breath and with strenuous heaves of her arms pulled herself underwater and into a fast breast-stroke. She kept her sister in her sights and strained to catch up on her. In her head she was adding her own dramatic music to the chase. “Der-DUH... Der-DUH... DUH-DUH-DUH-DUH-DUH-DUH-DUH-DUH” Her sister’s legs kicked in the water as she turned to see if Zara was gaining on her but Zara was a huge killer shark and was nowhere to be seen. Zara closed the distance, the music in her head spurring her on. Kelly frowned, suddenly suspicious. Three feet below her Zara The Shark let out a roar of bubbles and grabbed for her leg.
From her vantage point in the shallows Sarah heard Kelly scream and saw her pulled out of sight. There was a scuffle and fountains of water were thrown into the sky. Then Zara exploded from inside the frothing water, screaming with laughter and trying to swim to shore. Kelly burst to the surface seconds later, not laughing, and with a grim face she chased her sister down. When she had ducked her only sibling a few times the frown cracked and she smiled again.
The three girls floated face down in the water, blowing bubbles and looking for interesting oddities. Had they forgotten Brodie?
The girls found a calm patch of water and practiced sinking. They crossed their legs and held their noses and slipped down into the warm sea. After a little practice they could gently sink to the sandy bottom and sit like Buddah, grinning like crazy with their lips clamped shut. Kelly let bubbles spill upwards from her open mouth, thinking that if she sang a scale each bubble would contain one note and you might be able to hear it if you were close enough when it burst. Sarah thought that the three of them looked so comical that she let out a laugh. The air rushed out of her in a chaotic bubble and she swallowed some water. She kicked and struggled, trying to keep her mouth shut as she swam to the surface. Once back in the air she choked and spluttered and spat out the salty water. She tread water and calmed herself down with long, slow breaths. She was just about to sink to her companions again when they surfaced, on either side of her. They looked excited and Zara began to swim immediately in the direction of the currents that they had been told to avoid. Sarah looked questioningly at Kelly.
“Don’t worry, we saw something not to far away, come on!”
Kelly led and Sarah followed on her back, kicking her feet as fast as she could and sending up beautiful plumes of spray into the sky. The drops fell like rain on her face and she shut her eyes and smiled as wide as she could. In no time they were there and Kelly touched her head for her to stop.
“What is it?” There did not seem to be anything special about this spot of ocean.
“Look down there.” Kelly pointed down into the water beneath their feet.
Again Sarah held her breath and peered down to the bottom not far away. She could see a sort of sand bank with some abandoned sheet of metal on top of it. She could see Zara hauling herself down towards it through the water. Her fingers were outstretched, feeling for the solid surface that she had almost reached when suddenly...
Sarah came up for air and in the moment that she wasn’t watching there was a boiling and a massive movement deep under the water. Something huge rushed up towards her and Kelly carrying Zara with it. All around the two floating children the sea chopped itself into pieces and jumped up at the sky. A strange feeling that made them scream rushed up their legs. A living, moving creature thumped into them from underneath and the girls panicked. They thrashed their arms and kicked their legs and screamed at the top of their lungs. Even the adults far up the beach noticed the noise and looked up from their food to stare at them. Something grabbed Kelly and Sarah and the something made a noise,
“Chill! Chill Out! Calm Down! Relax! Oi! Oi! Hey!”
It was Zara with glee shining from her face.
“You have to try this,” she giggled at their frightened faces, “Hold your breath and follow me.”
She upended like a duck and dived quickly, Kelly and Sarah looked at each other sheepishly and dived after her.
They followed Zara down until their fingers caressed the smooth metal top of the underwater sand-dune. Sarah’s lungs began to hurt and she tapped Zara frantically. Zara smiled and held up one finger.
A second later the top of the dune opened and the biggest bubble that any of the girls had ever seen roared out of the hole. The bubble caught all three girls and waltzed them at full speed up to the surface.
After that there was no stopping them. They dived again and again to the metal sheet and dug their toes into the sand until the sheet lifted up like a trapdoor and fired them back to the surface. Then they sat cross legged around the magic door and when the bubble rushed out, always on time, they thrust their heads into the rising air and refilled their lungs. It was the greatest secret that they had ever known, to be able to stay underwater for minutes at a time. Sarah counted fish, Zara chased fish, Kelly investigated the magic trapdoor. The more she watched the bubble coming out the more she thought about where it might be coming from. The more she watched the trapdoor open the more manmade it looked to her. She started to experiment with the curious door. When it next opened she caught the door as it fell and held it open. She stared down into the constant stream of small bubbles that still came from the opening. She thought that she could see something but she wasn’t sure what it might be. Without the door shut there was no place for a big bubble to grow and the three girls had to return to the surface.
Brodie found his stick and looked around for the other kids but they were nowhere to be seen.
“I think that we should go inside.” Kelly was confident and curious.
“We know that there is lots of air inside anyway.” Zara thought that the metal dune was her discovery and she wouldn’t be satisfied until she had found out all about it.
“I think someone should stay on the outside, in case you can’t open it from the inside.” Sarah knew that they had been very lucky to be able to breathe under the sea and she didn’t feel like pushing that luck.
“Well that can be you,” decided Kelly, “We are going in.”
They all dived and took a breath from the mysterious trapdoor.
When next it opened Kelly grabbed it and nodded furiously at Zara. Zara, young though she was, dived into the blackness and disappeared. Kelly slipped in, feet-first and let the door shut behind her. Kelly and Zara were both too exhilarated to worry but Sarah on the outside was terrified for them. The seconds lengthened outside the strange sand-bank. Her heart beat in her ears, the air in her lungs tried to lever her head off to escape, she became sure that the big bubble would never come and whatever the fate of the sisters beyond the trapdoor she would drown. But just in time the bubble burst forth from the metal and she refilled her lungs.  A hand waved from beyond the door, beckoning her and she pushed down headfirst through the gap.
Inside the sand everything was pitch black. In the darkness she felt one arm around her from the left, one arm around her from the right, everyone was fine and she relaxed. The blackness was full of the bobble and rush of bubbles. They tickled her face and her feet.
Again the need for air came upon her, before her older friends and she wondered what was going to happen. She felt the girls beside her kicking and then he head broke the surface.
“Quick, breathe!” Someone shouted near her left ear.
“The door could open at any moment.” Someone said more slowly in her right ear.
She gulped in life-giving oxygen, thanking something for every bit.
As the bubble grew around her the sisters became sure that she was all right and they left her sides to search the underwater room with their fingertips. The floor was sand and the walls were all metal except one. The walls were at strange angles and their search found some long benches, riveted to the part of the ceiling that wasn’t steel. When the bubble was at full size there was only a foot or two of water left in the bottom of the room and both sisters splashed towards Sarah yelling,
“The door’s gonna/ Hold on/ Air’s gonna/ Hold your breath/ be OK!!”
BLLL-OP
Water rushed at them from all sides and the air leaped upwards like a balloon when you let go of the string. The girls held on and held their breaths.
Slowly air filled the dune again and they breathed again.
Kelly had had another idea,
“If we hold the door shut then the air won’t be able to escape and we won’t have to hold our breaths.”
She was so happy with the idea that she went to jam the door before she had finished speaking.
“Oh-No!”
Zara’s shout stopped her in her tracks.
“I’m not staying in here if I can’t swim out, No Way! No Way!”
“Then you can get out next time there is a bubble,” Kelly turned towards her, Sarah could hear it in the darkness, “Sarah?”
“I’m staying but we shouldn’t jam the door, I wouldn’t feel safe. We should just hold it shut and see what happens.”
Kelly didn’t want to have to bother holding the door shut herself but if Sarah would do it there was no point in complaining. “Okay.” She said and it was settled.
Zara was sucked up to freedom by the next big bubble and she lay, floating, on the surface and thought about the weird underwater room.
Inside the weird underwater room Sarah gripped tightly onto a handle that she had found in the underside of the door. More and more air built up around her until she was hanging in thin air. Kelly splashed around the interior of the metal box and investigated everything thoroughly, where the air was rushing in from underground, where the water was rushing in through various holes and cracks. She ran her fingers again and again over the smooth, non-metallic part of the ceiling and wondered about it.
Kelly was satisfied, after her search, that they were alone in the little man-made undersea cave but Sarah, hanging from the roof, was not so sure and she began to think that this odd box was the lair of some maneating monster, or worse a girleating monster. She was sure, now, that they would not drown but she worried that they were going to be the next meal of a mighty behemoth of the deep. She thought of all the fairy stories that she knew about the sea and that didn’t help. There was The Kraken and Leviathan and The Giant Squid. There were whales that swallowed people and boats. There were whole cities that had sunk under the sea. She could not think of any good stories about the sea at all and she started to cry, very quietly. She was sorry that she had ever dived down here and she forgot that to come back up she could simply have shouted a warning to Kelly and let go of the door, then let the bubble ride do the rest.
Then she though that something had gone wrong with her eyes because a line appeared across the blackness. It was a shining thread of light that wobbled in the air as if the air was water.
The thread thickened and then as if a switch had been thrown on a searchlight the little room filled to bursting with light. Kelly and Sarah squinted into the blaze and they made out a shadow. Their eyes got used to the light and they realised that the shadow was Zara waving in at them through a window in the ceiling. Zara quickly cleared more and more sand from the window until it was fully revealed, four meters long and two meters wide.
The sun shone down through the clear water and danced inside the upturned boat where the two girls were. One hanging from the roof, the other standing knee deep in the water.
Zara waved wildly through the huge window and grinned from ear to ear.
In a few minutes all three girls sat inside the relative dry of the sunken boat and gazed out of the window, up into the water. Kelly watched the underside of the breakers and spotted the keel of a surfboard cutting through the foam. Zara leaned against one crazily leaning wall and giggled at their discovery. Sarah knelt right up against the glass and stared and stared into the water, eating seafood with her eyes.
They stayed in their hideyhole for hours and hours, never thinking how their parents might be worrying about them, not considering what their parents might think had happened to their children. They watched the life of coastal waters going by, they sang songs to make the metal walls sing back to them with their funny, tinny voices, they fixed the inside of the boat up good with banks of almost dry sand to sit on and they looked out of the massive window at the world.
Even with the sun shining it was far from warm in the metal box and they were just about to leave when another magical thing happened.
First one, then two, then five dolphins sneaked cheekily up to their glass topped boat and looked in at them. The dolphins squeaked and blew bubbles and pushed against each other and the glass. The girls laughed and laughed, even more than they had when boshing in the waves. The dolphins seemed to laugh back and they waved their tails, stirring up clouds of sand that slowly settled back to sea-floor.
On the beach Brodie, who didn’t care about being forgotten, ran as fast as he could with his stick trailing in the soft sand. The stick cut easily into the powdered grains and threw up a bow wave on either side. The stick’s trail swooped across the beach, this way and that way, curving and turning back. Brodie yelled with delight and ran faster, his wee legs thundering across the flat beach. He was running for pure joy, he ran all over the beach, he watched his stick throwing up sand and painting a line behind him and he ran some more.
In their underwater headquarters the girls watched their graceful swimming cousins playing and racing each other. The song of the dolphins made the metal of the boat’s hull vibrate and they stood stock still listening. Sarah remembered that she had heard stories of dolphins saving sailors and swimming them to land, perhaps the sea was not as bad as she had thought.
As the sun started to sink from the sky the day started to end. Crustaceans withdrew into their shells, fish formed up into schools and swam for deeper water. The dolphins chased the fish and departed with them.
One dolphin waved its tail goodbye as another had waved its tail hello, then it bolted for the safety of its family. The girls unwedged the wedge that they had put in the door and POP POP POP they were fired back to the surface.
They swam slowly to the shore, talking about their adventure. They were met by the group of angry adults.
“You left your brother on his own!”
“What have you been doing?”
“Did you put on more sunscreen every time you came out of the water?”
“What have you got to say for yourselves?”
“I was so worried!”
“I almost called out The Air-Sea Rescue Helicopter, you could have been swept out to sea!” The adult enjoyed being dramatic now that everything was safe.
The grown-ups tumbled together all their food and bottles and chairs and umbrellas and towels and blankets and litter and made sure that all their children were accounted for.
“Where is Brodie?”
“He’s down by the sea.”
Brodie very carefully floated his stick and pushed it out into the big, blue ocean.
“Brodie!”
They went to the cars and loaded them up with stuff.
“Time to go home!”

The road rose slowly from the beach and since the cars were moving slowly the children were allowed to take off their seat-belts and kneel up to look out of the back window and down to the beach they had left.
As they looked back down at where they had come from all three girls opened first their eyes and then their mouths. From this distance and this height they stared in wonder at the patterns made by Brodie and his little stick.
The length of the beach, from the black rocks to the tough beach grass called machair, clearly and cleanly, Brodie had drawn, without knowing it, a family of five dolphins in a row.