Swimmers prepare for heat during Tolo Harbour swimming event

The 53rd Cross Tolo Harbour Open Race kicks off under the Very Hot Weather Warning today.

Event organiser says they lowered the threshold for race cancellation in response to previous drownings.

The event drew in 710 swimmers between the ages of 10 and 77 years old.

Kicking off at Shuen Wan Sha Lana at 10:30 this morning, it ended at the Tai Mei Tuk Water Sports Centre, spanning a total of 2,600 metres.

This year's event saw a 20-percent spike in applicants year-on-year, with organisers saying they have strengthened safety measures to prevent further drownings.