Scuba diving offers a respite from the relentless pressures of city life, especially its noise, dirt and air pollution.
It also offers the chance to see the enchanting sea creatures that share more than two-thirds of our planet's space with us.
Contrary to conventional wisdom, scuba diving is not dangerous if you are well-trained, have the appropriate equipment and stick to the rules.
It is also a fun sport suitable for most people.
'Scuba diving is even possible for people with physical disabilities,' says instructor Daniel Yau, who has difficulty walking as a result of contracting polio when he was a child.
'The buoyancy of water makes the body more weightless and this frees disabled people from many of their disadvantages of movement.'