Basalt Island, in Hong Kong’s Sai Kung district, was supposed to be a summer escape. It was July 2020, early in the Covid-19 pandemic, and Jennifer Wannenmacher and her family had joined a group of friends for a day of coasteering along the island’s rugged coastline.The activity involved traversing the shoreline on foot, jumping into the water where cliffs ended, swimming to the next ledge, and clambering out to continue the journey. There were eight adults and three children in total, including Wannenmacher’s husband and kids, then aged six, eight and nine.The water was calm when they started, but halfway through, the swells turned choppy and unpredictable. Suddenly, her children could not time the waves to hoist themselves onto a slick rock face. They were slipping. The current threatened to pull them into open water.“I started to panic,” Wannenmacher says. “But then muscle memory kicked in.”She called on a move called a barbell thruster, performing it in open water with no floor to push against.“I had to tread water, and when I was ready, I kicked out of the water while thrusting my child up onto the rock face,” she says. “By this time, one of the dads had managed to climb out and was waiting to grab the child I was thrusting upwards.”Jennifer Wannenmacher and her family on a holiday in the Philippines in 2017. Photo: Jennifer Wannenmacher