During parent/child classes we require each parent to wear a rash shirt rather than a T-shirt. This ensures the pool water is kept clean by keeping lint to a minimum (with the exception to clothing swim week).
A rash shirt also aids the process of your child learning to swim.
A child learns very early the grasp action using their finer motor skills and as a safety precaution we like to utilise this reflex action in swimming. As your child begins to relax while submerging you will find it very useful to allow your child to grasp on to your rash shirt rather than you picking them up.
Keep in mind this is a gradual process and in no way should you wait for your child to grasp on to you unless they were comfortable in submerging.