A private swimming instructor for kids is a viable option for people who can afford it. Private swimming instructors might be a little more expensive because the teacher will be giving the kid more attention.
The best private swimming instructor for kids will have a well established reputation. This does not mean that the instructor will have a great google rating. Google ratings can be easily rigged and sabotaged. However, it means that the instructor will have happy clients who refer the person. They say that word of mouth is the best way to know if someone is worth their salt. Find a person who people in the city are saying helped their kids.
Also, a private swimming instructor for kids should be flexible. It is fine if someone is highly recommended, but if they are not available at a mutually convenient time, then they will have to be crossed off the list. A parent cannot make kids stay up past their bedtime, for example, to have a swimming lesson in Singapore. A person needs to be able to have their kids stay healthy throughout the lesson process. That means very early mornings or late nights should be a no go zone even if the private instructor is willing to make it happen.
A teacher needs to have experience with a certain type of child. If the child has needs that a parent wants accommodated, the teacher should be able to come up with a solution as to how the need can be met. Otherwise, the lessons are likely to be a waste of time. If the instructor for example does not know how to help a child with a phobia of water, then perhaps someone who has helped other fearful children in the past is a better choice. Alternatively, the teacher should be willing to research and try out some theories even if they don’t have prior experience.