The hot sunny weather recently has been beach weather. And so I went to Yellowcraig with my daughters. When we arrived the tide was out.

“Perfect,” I said. We walked to the edge of the beach, and I lifted my oldest daughter Mairi onto a rock and left her there! Then my five-year-old Manja wanted to join her.

“We can’t get off, the tide is coming in!” Mairi called out. “I know,” I replied, “I just want a photo.” “Oh no, it’s for another story!” she said.

She was right: Once upon a time, but not so long ago, an old fisherman was walking along the beach at Yellowcraig. He sat on one of the many rocks at the shore and looked out to sea. It was low tide but the sea was now slowly returning. Lots of rocks all around him formed tiny islands, and soon they would be covered by the approaching returning sea.

But beyond the rocky shoreline the island called Fidra stood firm and undaunted in the water. He first landed on the island one spring many years ago with his father, who was also a fisherman. He was then just a lad, learning his father’s trade, and the day they landed and scrambled across the rocks to explore the island was one he had never forgotten.

That day the noise of the birds was almost deafening and it seemed that except for the recently built lighthouse there was no sign of human occupation. But then his father showed him the remains of an old castle. Not much was left of it, as 900 years of sea air and storms had reduced it to a stub of masonry. But enough remained to be a memorial of past status. He sat with his father by the great arch of volcanic rock that made it seem the island was leaning on itself as his father told him some of the island’s secrets.

He told how the island had been a home for holy men, as well as nobles; that it was visited by Vikings, who have left traces in the imagination. His father showed him where a holy man once lived in days when the dawn of Christianity was just breaking over this shore. They found a skull, close to where there was once a community of those with leprosy or the plague. There were tales of wreckers and smugglers, and seafarers stranded.

But then his father told him another secret about the island. One he had to keep to himself. And since that day the secret had remained with him.

He revisited Fidra many times after that first time, but never again with his father, who had been an ill man. His visits were remarked upon. He told those curious that he enjoyed the solitude of the place. Sometimes he stayed longer than a day. Folk wondered if he was mad, or just lonely. Who would want to spend a night on such a lonely, windswept place? At times the lighthouse men saw him, but it was fleeting glimpses. Maybe they discovered his secret but also kept it to themselves.

As he grew old he visited less. His hands swelled with the cuts and strains of his trade and his bones had began to ache. Age had crept upon him like a stalker in the dark. He still called himself a fisherman, even though he no longer went to sea fishing. Instead of visiting the island he would walk on Yellowcraig Beach, and wait just where the rocks meet the blanket of sand at low tide, as he was doing on this day.

He scanned the island with his ageing eyes. It stood before him as it always had, close but yet also strangely distant, only 300 metres from the shore, yet part of a different world.

Then his eyes lowered and he studied the sea between the shore and the island silhouette. He was waiting for something, or someone.

A movement in the water made him nervous. The direction of his glance changed and now his head swirled round like an eagle’s as he studied the shoreline and the beach on both sides. He was alone, totally alone on the windswept beach.

Then he wasn’t. She emerged slowly at first, her head dipping above the surface, checking all was clear. Then the seal swam with purpose to the rock on which he had left his sack. The sack vanished and a moment later a woman appeared from where the seal had been.

She was of course a Selkie. She walked towards the old fisherman, her face decorated with a smile. The fisherman’s face lit up, and he opened his arms and wrapped them around her as she nestled into his embrace.

“Hello father,” she said, “I have missed you.” Many years before, on that day with his own father on the island, the secret he was told was that of the Selkies. They watched secretly as they came ashore on the far side of the island. A seal when in water, a Selkie can remove its coat and become human. The old fisherman was then a young lad and never before had he seen creatures of such beauty and enchantment.

But his father warned him: “Remember son, they are not human, they are Selkies. I show you this because such wonders need to be shared, and respected. A fisherman needs to understand not to harm them in any way. They are one of the wonders of the seas. But admire their beauty secretly from afar. Never fall in love with them. They will only break your heart. And keep this a secret, there are those who would seek to capture or harm them.” His father died soon afterwards, so the old fisherman revisited the island alone. At first he had followed his father’s advice. How many times he had watched secretly from the rocks he didn’t know. But one day it all changed.

It was a day of storms, yet it had been calm when he had arrived on the island. Only one Selkie arrived this day, and as she wandered from the shore her coat was picked up by a swirl of wind and thrown into a bracken-covered slope.

The fisherman watched as the young woman searched frantically for her coat. Without it she would be unable to return to the sea. Her mood turned into panic, then into desperate wails. He could stand her distress no longer and called out to her.

“Over there, in the bracken, the wind threw it there.” She had vanished before he had even finished the words, hiding somewhere among the rocks. And so he left his hiding place and went to the slope. Sure enough, there was the Selkie coat. He picked it and held it. It was smooth and warm. Then he placed it on a rock close to the shore and returned to his hiding place. He watched as the woman cautiously emerged from the rocks. She took the coat, wrapped it round herself but just before she transformed she looked up to where the fisherman was hiding. He stood up and for a glancing moment their eyes met. Then a seal then swam away.

That night the fisherman couldn’t get the image of the Selkie girl out of his mind. He was then a young man, and wanted a wife. Surely a Selkie would make a perfect wife. He was smitten.

And so he returned again and again; until one day his obsession made him venture to the island when any fisherman would have told him that the sea was too angry to risk a voyage. His small boat filled with water as the waves raged over it, and soon he found himself sinking in freezing sea water.

Then, as consciousness was fading, arms surrounded him and he was next on the beach. A beautiful woman sat by him as he woke. It was the Selkie girl.

Their love affair was secret and brief. They would meet on the island, away from prying human eyes. Sometimes at night they would walk on the soft sand at Yellowcraig. Inevitably he asked her to marry him and she agreed. Soon she became pregnant and a baby girl joined them.

She loved her fisherman but she realised she loved the sea more. She would return to the sea regularly, and each time her return took longer, until one day she didn’t return.

The fisherman remembered his father’s words: “Admire their beauty secretly from afar. Never fall in love with them. They will only break your heart.” But he understood that the Selkie wasn’t bad. She was just too unhappy where she was.

Heartbroken, the fisherman returned to the island secretly once again, and watched. Selkies came and went but not his wife and daughter. Until one day, almost when he had given up, they both appeared.

“Here,” said his wife, “here is your daughter. She is half of you and half of me. She is half Selkie and half human. I cannot rejoin you but she needs you and your world as much as she needs me and mine.” And so the fisherman would return to the island to be with his daughter. She loved the sea, but also loved the land. She was part of both. She loved swimming with her mother and walking with her father. She shared both their worlds.

As her father grew old he found it more difficult to visit her on the island, but instead they met on the shore. He would bring her clothes in a sack and she would walk with her father in the nearby woods, and they would talk and pick berries.

They met when the tide was low, by a rock close to the sandy beach. Sometimes people saw them walking or sitting together, but never when they met or parted.

So nobody knew why the old fisherman sat on the rock looking out to the sea towards Fidra. When he too passed away, the secret went with him. Until now.