Colorful flags snapped in the sea breeze as more than a dozen Korean shamans, dressed in bright colors, danced and chanted prayers in front of a huge cow's head stuck to a trident.
The ceremony on a ship was designed to exorcise demons that threaten fishermen and bring good luck to everybody on board. The presence of several hundred spectators underlined how the ages-old trance rituals were going strong again, having been shunned as recently as 30 years ago.
"People are trying to understand more, learn more, and see more. They are very interested in this," said Kim Keum-hwa, one of South Korea's most famous shamans, who led the ceremony.
Though an ancient practice, Korean shamanism - in which singing and dancing are used in trance rituals addressed to specific gods, often to get an answer to specific questions - had long been suppressed in Asia's second most Christian nation.
In leaping from poverty to rapid modernization, the county's dictatorship in the 1970s tried to eliminate shamanism, claiming that shamans deluded the world, while some Christian missionaries demonized them and their followers.
But today, visiting a mudang - shaman priest or priestess - is so common that politicians consult them seeking answers to questions such as whether they should relocate their ancestors' remains to ensure good luck in the next election. Shaman characters have also featured in popular television shows.
"Public perception towards shamanism has improved a lot, with popular TV dramas contributing to shifting these views," said Park Heung-ju, an authority on mudang at the Kut Research Institute in Seoul."You can find repose by meeting with mudang."
Much of this is due to the pressures of modern life in South Korea's high-stress society, said Shin Kwang-yeong, a sociology professor at Chung-Ang University in Seoul.
"Nowadays, many Koreans feel strong uncertainties and life seems unstable in many ways, so they want to find something that can give them a sense of security," he said. "The same things have also created a dramatic increase in the number of people who follow religions here in Korea."
To start the on-board ceremony, the shamans light a bundle of straw and float it on the water with offerings of food to exorcise evil spirits.
Later they go into a trance, speaking directly to spectators to wish them good luck and good health to the accompaniment of lively music from pipes, flutes and drums.
At the end, shamans and spectators mingle as one group, dancing in a circle to the fast-paced music.
"Shunning shamanism is not right. Today's event is meant to be for praying for the sake of families," said Lee Sung-soo, who said he was a Buddhist but danced with the group nonetheless.
In one sign of how mainstream shamanism has become, one mudang shaking bells in front of the laden altar was Hendrikje Lange from Switzerland, who credits shamanism with lifting her out of a debilitating depression.
Lange, 45, encountered shamanism as part of her studies of Korean percussion instruments, but resisted actually taking part in a possession ritual until several accidents and visions convinced her she needed to change her life.
Now, she is one of dozens of shamans initiated by Kim, including a handful of foreigners.
"All I can say is that something is happening with energy. I feel that the longer it keeps going, the stronger the energy is," she said.
Shin, the sociologist, said an additional part of the mudang's appeal was the sense that it was personal.
"People may have faith in other religions, but those religions seem vague and not tailored to them personally," he said. "People go to see shamans because they all believe their stories and situations are unique."
Jung Mi-soon, a participant in the ceremony, said that shamanism spoke to her directly.
"I felt something from my heart. This ritual has everything in there - happiness, sadness, anger and fun," said the 46-year-old housewife who has had more than 10 surgeries which she attributes to spiritual sickness.
"Sometimes tears pour out from my heart. Sometimes it's just fun when everyone is dancing and bowing. And, it's healing."