Oh Ok, I understand now. I was just in Shenzhen (and Hong Kong) last month and took the metro from Shenzhen Airport to Kowloon in almost 2 hours.
You can get to some of the hikes in 3 hours (+/- 1 hour) depending where you're coming from.
If you decide to go, I can give you written instructions on how to get to the beaches I visited - you can email me at
David@DavidDawei.com