Selkies are rare and mysterious creatures. Although, some do occassionally spend time on land. When they form connections with humans, the resulting stories are as old as time immemorial and they usually go something like this:

There was once an English fisherman who encountered a beautiful woman sunbathing nude by the sea. He was so entranced, that he fell immediately and completely in love with her. Unfortunately, when the woman saw him approaching, she grabbed something from a nearby rock and dove into the sea.
The man was heartbroken, thinking he may never see her again, never know her name, and never speak to her. He came back to the same spot day after day to see if she would return. After months of waiting, one day, she did. The man watched from a rock above as the woman emerged from the sea, shedding her seal skin as she went. In that moment, he knew she was a selkie.
His infatuation for her was so strong that he hatched a plan – he would steal her selkie skin, forcing her to stay on land in her human form.
So, he snuck down the rocks and, when she wasn’t looking, secreted her selkie skin away. After hiding it safely in his small house, he returned to find her distraught. Although he was the cause of her distress, he pretended not to know who she was and to help her look. When the skin could not be found, he gave her a place to stay and food to eat.
Over time, the Selkie fell in love with the man as well. The couple married and had children. All was well until one day, the couple’s young son found a package hidden up the chimney. He pulled it out and showed it to his mother who, upon seeing the selkie skin, grabbed it and fled back to the sea. Although she loved her family, her thirst for freedom and the open sea was too strong for her to remain on land.
Although this story has a sad ending with a few troubling elements (a peeping Tom, deceit, and Stockholm syndrome for starters), it is woven with fascinating elements like the existence of wild creatures who can live both on land and in the water, and whose hearts belong so fully to the sea that nothing could hold them back.
So what happens when you give a selkie their coat?
According to ancient legend, if you give a selkie their coat, they run for the sea, never to be seen or heard from again. But like most stories told by jilted lovers, this is likely an oversimplification. After all, selkies are every bit as loving and passionate as their human counterparts, if not moreso.
For most selkies, if the love is true, they won’t run away.
That being said, if the love was true, involuntary capture wouldn’t have been necessary in the first place.