Ask for certification:
There are many differently certificates to qualify one to teach swimming. However in Singapore, any coach who wants to teach in a public pool has to be registered with the Singapore Sports Council (SSC). To be registered, one need to be certified by the Singapore Swimming Association (SSA) and must possess valid lifesaving and CPR certificates such as the Bronze Medallion and CPR certs. All registered coaches carry a green IC sized identity card issued by SSC.
Check online:
Another way to check if your swimming instructor is registered and certified is to visit the Singapore Sports Council's coaching website and do a search for the instructor's name (click here). Read below for instructions to perform search:
key in Name of instructor
Select swimming under sports
leave level as "All"
All registered and certified coaches will be given a page like this.
There are alleged cases of coaches taking in students without proper certification so do verify your coach's qualification.