Her sister, Madhushika Subhashini, aged 26, is the other female licensed diver of the area.
Following the end of the war in 2006, tourism saw a rapid development at Kalpitiya.
In 2014, the two sisters got involved in a campaign by environmental groups to protect the endangered coral reefs of Kalpitiya, BBC Sinhala Service reports.
They dive, and remove garbage from the coral reef, and carry out other activities to protect it.
Kalpitiya has a UNDP project for the promotion of biodiversity and environmental system maintenance in environmentally sensitive locations.
Grown by 10 pc
Sumith, who counts more than 20 years in experience as a diver, says the Kalpitiya coral reef had been destroyed 95 per cent when the project started, but now has grown by 10 pc now.
The two sisters led an undersea engagement ceremony at Kalpitiya recently too.