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Close to the border with North Korea, the sea teems with small South Korean fishing boats.

It is early in the morning and a plentiful fishing ground, which has been closed for the winter, is about to be opened up to the eager divers on board the boats.

They know a bountiful catch awaits the quickest and bravest among them.

But this sea holds many dangers, especially for compressor divers like 50-year-old Park Myongho.

Park saved money, bought a house and a boat and even opened a seafood restaurant. But he is still restless in South Korean society. The fear and the horror of the day when he and his family escaped from North Korea has just been replaced with the fear and the horror that anything could happen in the sea.

Jin Mo-young, filmmaker, Old Marine Boy

Wearing a heavy diving suit, helmet and lead weights, Park relies upon a single hose to deliver air to him as he tries to catch octopuses and other sea creatures on the seabed. If the hose gets tangled up or caught on something, it means certain death.

"A compressor diver is always standing between life and death," Park explains.

He has seen other divers die and knows that even for those who survive, the long-term health consequences of such a dangerous profession can be severe.

But this isn't the only danger he faces.

If he ventures too close to the border with North Korea, he could run afoul of one of the warships that patrol the area. And he understands only too well what this would mean; Park is a defector from North Korea.

After spending 20 years in the North Korean military, Park persuaded his wife that they should flee with their two sons. He cannot forget the fear he felt that night, but life in South Korea hasn't quite provided the peace of mind he'd hoped for.

With no support network, he worries constantly about one day being unable to provide for his family. It is this fear that wakes him at 5am each morning, taking him out to sea, where he pushes his body and endangers his life in his underwater netherworld.

'A compressor diver is always standing between life and death,' says North Korean defector Park Myongho [Jin Mo-young/Al Jazeera]

Source: Al Jazeera