Ang first represented Singapore at the 1977 Southeast Asian Games in Kuala Lumpur, where he won a silver medal in the 4 × 100 m freestyle relay.

[5] As a result of his performance in Hawaii, Ang received an offer for a full athletic scholarship from American swimming coaches Phil Hansel and Jim Montgomery to study physical education at the University of Houston.

Ang represented Singapore at the 1984 Summer Olympics in Los Angeles, where he won the 'B' consolation final in the 100 m freestyle.

His time of 22.69 seconds stood as a Singapore national record for 33 years until Joseph Schooling broke it at the 2015 SEA Games.

He has worked with swimmers at all levels – from young children just learning how to swim, to national champions preparing to represent Singapore at top international competitions.