A 59-year-old man died after being trapped underwater between rocks while diving off Tung Lung Chau to the east of Shek O yesterday.
This is the second diving fatality in three days. The other saw a woman drowned in Sai Kung.
The man, Lee, was declared dead at Pamela Youde Nethersole Eastern Hospital in Chai Wan around 2pm.
Lee went underwater diving off Tung Lung Chau with three friends around 11am, during which he and a companion dove into the water first.
Shortly afterward, Lee's companion surfaced to get help from the others after finding Lee trapped between rocks.
Lee's companion dived again, tried to pull him free to no avail and got into trouble himself.
The Fire Services Department, Government Flying Service and police were called in. Divers first rescued Lee's companion and continued to search for Lee in the meantime.
At 12.35pm, Lee was retrieved. He was taken to a pier near Siu Sai Wan sports ground before being transferred to Pamela Youde Nethersole Eastern Hospital, where he was declared dead.
Scuba diving instructor at The National Association of Underwater Instructors Oliver Ng Yau-cheong said the Tung Lung Chau waters were not considered too risky for experienced divers, but it was the weather that made it dangerous.
"There was an easterly wind ongoing and the weather was relatively windy - the wind was on level four to five [moderate to fresh wind speed]," he said.
"Divers should select places that can shield them from the strong wind for diving, such as enclosed reservoirs and waters near a mountain."
He said if divers get stuck under rocks in the waters, they should remain calm by taking deep breaths as they figure out a way to free themselves.
"Divers should also avoid diving in spots with fierce currents and take courses that teach them how to rescue themselves under certain situations," he said.
Hong Kong Technical Diving Association Johnny Lee Hak-keung said open waters, such as that of Tung Lung Chau, mean that currents are restless.
"This is testing on divers' floating ability when they go against the current," he said.
On the deceased man, he said the man could have been trapped underwater by abandoned fishing nets scattered around the rocks, known as "ghost gear."
"Divers' flippers may get tangled up with the "ghost gear," but they should not struggle wildly as the more they struggle, the harder it is for them to be freed," he said.
"Instead, they should stay calm and take off the flippers to slowly untangle themselves ."